1.10.0

* Refactoring Superuser contract to allow Owners to transfer ownership when they are not superusers #50

* Refactoring tests to create a contract instance for each of them #50

.gitattributes

@@ -0,0 +1 @@
+*.sol linguist-language=Solidity

.github/ISSUE_TEMPLATE.md

@@ -0,0 +1,34 @@
+## 🎉 Description
+
+<!-- Briefly describe the issue you are experiencing (or the feature you want to see added to OpenZeppelin). Tell us what you were trying to do and what happened instead. **Remember, this is _not_ a place to ask for help debugging code; for that, we welcome you in the [OpenZeppelin Slack Channel](https://slack.openzeppelin.org/).** -->
+
+- [ ] 🐛 This is a bug report.
+- [ ] 📈 This is a feature request.
+
+<!-- Please check one of the above by placing an x in the box. -->
+
+## 💻 Environment
+
+Next, we need to know what your environment looks like.
+
+- Which version of OpenZeppelin are you using?
+- What network are you deploying to? Ganache? Ropsten?
+- How are you deploying your OpenZeppelin-backed contracts? truffle? Remix? Let us know!
+
+## 📝 Details
+
+Describe the problem you have been experiencing in more detail. Include as much information as you think is relevant. Keep in mind that transactions can fail for many reasons; context is key here.
+
+## 🔢 Code To Reproduce Issue [ Good To Have ]
+
+Please remember that with sample code it's easier to reproduce the bug and it's much faster to fix it.
+
+```
+insert short code snippets here
+```
+
+<!-- If your code is larger, consider linking us to a repo illustrating your issue. -->
+
+## 👍 Other Information
+
+<!-- List any other information that is relevant to your issue. Error logs, related issues, suggestions on how to fix, Stack Overflow links, forum links, etc. -->

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,17 @@
+<!-- 0. 🎉 Thank you for submitting a PR! -->
+
+<!-- 1. **Does this close any open issues?** If so, list them here. If not, remove the `Fixes #` line. -->
+
+Fixes #
+
+# 🚀 Description
+
+<!-- 2. Describe the changes introduced in this pull request -->
+<!--    Include any context necessary for understanding the PR's purpose. -->
+
+<!-- 3. Before submitting, please review the following checklist: -->
+
+- [ ] 📘 I've reviewed the [OpenZeppelin Contributor Guidelines](../blob/master/CONTRIBUTING.md)
+- [ ] ✅ I've added tests where applicable to test my new functionality.
+- [ ] 📖 I've made sure that my contracts are well-documented.
+- [ ] 🎨 I've run the JS/Solidity linters and fixed any issues (`npm run lint:all:fix`).

.soliumrc.json

@@ -1,22 +1,14 @@
 {
-  "custom-rules-filename": null,
+  "extends": "solium:all",
+  "plugins": ["security"],
   "rules": {
-    "imports-on-top": true,
-    "variable-declarations": true,
-    "array-declarations": true,
-    "operator-whitespace": true,
-    "lbrace": true,
-    "mixedcase": false,
-    "camelcase": true,
-    "uppercase": true,
-    "no-with": true,
-    "no-empty-blocks": true,
-    "no-unused-vars": true,
-    "double-quotes": true,
-    "blank-lines": true,
-    "indentation": true,
-    "whitespace": true,
-    "deprecated-suicide": true,
-    "pragma-on-top": true
+    "quotes": ["error", "double"],
+    "no-empty-blocks": "off",
+    "indentation": ["error", 2],
+    "max-len": ["warning", 79],
+    "no-constant": ["error"],
+    "security/enforce-explicit-visibility": ["error"],
+    "security/no-block-members": ["warning"],
+    "security/no-inline-assembly": ["warning"]
   }
 }

.travis.yml

@@ -10,14 +10,17 @@ cache:
 env:
   -
   - SOLIDITY_COVERAGE=true
+  - SOLC_NIGHTLY=true
 matrix:
   fast_finish: true
   allow_failures:
     - env: SOLIDITY_COVERAGE=true
+    - env: SOLC_NIGHTLY=true
 before_script:
   - truffle version
 script:
   - npm run lint
+  - npm run lint:sol
   - npm run test
 notifications:
   slack:

CONTRIBUTING.md

@@ -1,107 +1,58 @@
-Contributing to Zeppelin
+Contributing to OpenZeppelin
 =======
 
-## Design Guidelines
+We really appreciate and value contributions to OpenZeppelin. Please take 5' to review the items listed below to make sure that your contributions are merged as soon as possible. 
 
-These are some global design goals in Zeppelin.
+## Contribution guidelines
 
-### D0 - Security in Depth
-We strive to provide secure, tested, audited code. To achieve this, we need to match intention with function. Thus, documentation, code clarity, community review and security discussions are fundamental.
+Smart contracts manage value and are highly vulnerable to errors and attacks. We have very strict guidelines, please make sure to review them: ["Contribution guidelines wiki entry"](https://github.com/OpenZeppelin/openzeppelin-solidity/wiki/Contribution-guidelines).
 
-### D1 - Simple and Modular
-Simpler code means easier audits, and better understanding of what each component does. We look for small files, small contracts, and small functions. If you can separate a contract into two independent functionalities you should probably do it.
+## Creating Pull Requests (PRs)
 
-### D2 - Naming Matters
+As a contributor, you are expected to fork this repository, work on your own fork and then submit pull requests. The pull requests will be reviewed and eventually merged into the main repo. See ["Fork-a-Repo"](https://help.github.com/articles/fork-a-repo/) for how this works.
 
-We take our time with picking names. Code is going to be written once, and read hundreds of times. Renaming for clarity is encouraged.
+*IMPORTANT* 
+* Please see ["Git flow wiki entry"](https://github.com/OpenZeppelin/openzeppelin-solidity/wiki/Git-flow) for understanding how to use branches in this repository.
 
-### D3 - Tests
+## A typical workflow
 
-Write tests for all your code. We encourage Test Driven Development so we know when our code is right. Even though not all code in the repository is tested at the moment, we aim to test every line of code in the future.
+1) Make sure your fork is up to date with the main repository:
 
-### D4 - Check preconditions and post-conditions
+```
+cd openzeppelin-solidity
+git remote add upstream https://github.com/OpenZeppelin/openzeppelin-solidity.git
+git fetch upstream
+git pull --rebase upstream master
+```
+NOTE: The directory `openzeppelin-solidity` represents your fork's local copy.
 
-A very important way to prevent vulnerabilities is to catch a contract’s inconsistent state as early as possible. This is why we want functions to check pre- and post-conditions for executing its logic. When writing code, ask yourself what you are expecting to be true before and after the function runs, and express it in code.
-
-### D5 - Code Consistency
-
-Consistency on the way classes are used is paramount to an easier understanding of the library. The codebase should be as unified as possible. Read existing code and get inspired before you write your own. Follow the style guidelines. Don’t hesitate to ask for help on how to best write a specific piece of code.
-
-### D6 - Regular Audits
-Following good programming practices is a way to reduce the risk of vulnerabilities, but professional code audits are still needed. We will perform regular code audits on major releases, and hire security professionals to provide independent review.
-
-## Style Guidelines
-
-The design guidelines have quite a high abstraction level. These style guidelines are more concrete and easier to apply, and also more opinionated.
-
-### General
-
-#### G0 - Default to Solidity's official style guide.
-
-Follow the official Solidity style guide: https://solidity.readthedocs.io/en/latest/style-guide.html
-
-#### G1 - No Magic Constants
-
-Avoid constants in the code as much as possible. Magic strings are also magic constants.
-
-#### G2 - Code that Fails Early
-
-We ask our code to fail as soon as possible when an unexpected input was provided or unexpected state was found.
-
-#### G3 - Internal Amounts Must be Signed Integers and Represent the Smallest Units.
-
-Avoid representation errors by always dealing with weis when handling ether. GUIs can convert to more human-friendly representations. Use Signed Integers (int) to prevent underflow problems.
-
-
-### Testing
-
-#### T1 - Tests Must be Written Elegantly
-
-Style guidelines are not relaxed for tests. Tests are a good way to show how to use the library, and maintaining them is extremely necessary.
-
-Don't write long tests, write helper functions to make them be as short and concise as possible (they should take just a few lines each), and use good variable names.
-
-#### T2 - Tests Must not be Random
-
-Inputs for tests should not be generated randomly. Accounts used to create test contracts are an exception, those can be random. Also, the type and structure of outputs should be checked.
-
-
-### Documentation
-
-TODO
-
-## Pull Request Workflow
-
-Our workflow is based on GitHub's pull requests. We use feature branches, prepended with: `test`, `feature`, `fix`, `refactor`, or `remove` according to the change the branch introduces. Some examples for such branches are:
-```sh
-git checkout -b test/some-module
-git checkout -b feature/some-new-stuff
-git checkout -b fix/some-bug
-git checkout -b remove/some-file
+2) Branch out from `master` into `fix/some-bug-#123`:
+(Postfixing #123 will associate your PR with the issue #123 and make everyone's life easier =D)
+```
+git checkout -b fix/some-bug-#123
 ```
 
-We expect pull requests to be rebased to the master branch before merging:
-```sh
-git remote add zep git@github.com:OpenZeppelin/zeppelin-solidity.git
-git pull --rebase zep master
+3) Make your changes, add your files, commit and push to your fork.
+
+```
+git add SomeFile.js
+git commit "Fix some bug #123"
+git push origin fix/some-bug-#123
 ```
 
-Note that we require rebasing your branch instead of merging it, for commit readability reasons.
+4) Go to [github.com/OpenZeppelin/openzeppelin-solidity](https://github.com/OpenZeppelin/zeppelin-solidity) in your web browser and issue a new pull request.
 
-After that, you can push the changes to your fork, by doing:
-```sh
-git push origin your_branch_name
-git push origin feature/some-new-stuff
-git push origin fix/some-bug
-```
+*IMPORTANT* Read the PR template very carefully and make sure to follow all the instructions. These instructions 
+refer to some very important conditions that your PR must meet in order to be accepted, such as making sure that all tests pass, JS linting tests pass, solidity linting tests pass, etc.
 
-Finally go to [github.com/OpenZeppelin/zeppelin-solidity](https://github.com/OpenZeppelin/zeppelin-solidity) in your web browser and issue a new pull request.
+5) Maintainers will review your code and possibly ask for changes before your code is pulled in to the main repository. We'll check that all tests pass, review the coding style, and check for general code correctness. If everything is OK, we'll merge your pull request and your code will be part of OpenZeppelin.
 
-Main contributors will review your code and possibly ask for changes before your code is pulled in to the main repository.  We'll check that all tests pass, review the coding style, and check for general code correctness. If everything is OK, we'll merge your pull request and your code will be part of Zeppelin.
+*IMPORTANT* Please pay attention to the maintainer's feedback, since its a necessary step to keep up with the standards OpenZeppelin attains to.
 
-If you have any questions feel free to post them to
-[github.com/OpenZeppelin/zeppelin-solidity/issues](https://github.com/OpenZeppelin/zeppelin-solidity/issues).
+## All set!
 
-Finally, if you're looking to collaborate and want to find easy tasks to start, [look at the issues we marked as easy](https://github.com/OpenZeppelin/zeppelin-solidity/labels/easy).
+If you have any questions feel free to post them to github.com/OpenZeppelin/openzeppelin-solidity/issues.
+
+Finally, if you're looking to collaborate and want to find easy tasks to start, look at the issues we marked as ["Good first issue"](https://github.com/OpenZeppelin/openzeppelin-solidity/labels/good%20first%20issue).
 
 Thanks for your time and code!

README.md

@@ -1,7 +1,7 @@
-# Zeppelin Solidity
-[![NPM Package](https://img.shields.io/npm/v/zeppelin-solidity.svg?style=flat-square)](https://www.npmjs.org/package/zeppelin-solidity)
-[![Build Status](https://img.shields.io/travis/OpenZeppelin/zeppelin-solidity.svg?branch=master&style=flat-square)](https://travis-ci.org/OpenZeppelin/zeppelin-solidity)
-[![Coverage Status](https://img.shields.io/coveralls/github/OpenZeppelin/zeppelin-solidity/master.svg?style=flat-square)](https://coveralls.io/github/OpenZeppelin/zeppelin-solidity?branch=master)
+# OpenZeppelin Solidity
+[![NPM Package](https://img.shields.io/npm/v/openzeppelin-solidity.svg?style=flat-square)](https://www.npmjs.org/package/openzeppelin-solidity)
+[![Build Status](https://img.shields.io/travis/OpenZeppelin/openzeppelin-solidity.svg?branch=master&style=flat-square)](https://travis-ci.org/OpenZeppelin/openzeppelin-solidity)
+[![Coverage Status](https://img.shields.io/coveralls/github/OpenZeppelin/openzeppelin-solidity/master.svg?style=flat-square)](https://coveralls.io/github/OpenZeppelin/openzeppelin-solidity?branch=master)
 
 OpenZeppelin is a library for writing secure [Smart Contracts](https://en.wikipedia.org/wiki/Smart_contract) on Ethereum.
 
@@ -13,7 +13,11 @@ With OpenZeppelin, you can build distributed applications, protocols and organiz
 
 ## Getting Started
 
-OpenZeppelin integrates with [Truffle](https://github.com/ConsenSys/truffle), an Ethereum development environment. Please install Truffle and initialize your project with `truffle init`.
+OpenZeppelin integrates with [Truffle](https://github.com/ConsenSys/truffle) and [Embark](https://github.com/embark-framework/embark/).
+
+## Truffle
+
+To use with Truffle, first install it and initialize your project with `truffle init`.
 
 ```sh
 npm install -g truffle
@@ -21,22 +25,46 @@ mkdir myproject && cd myproject
 truffle init
 ```
 
-To install the OpenZeppelin library, run:
+## Embark
+
+To use with Embark, first install it and initialize your project with `embark new MyApp`.
+
 ```sh
-npm init
-npm install zeppelin-solidity
+npm install -g embark
+embark new MyApp
+cd MyApp
 ```
 
-After that, you'll get all the library's contracts in the `node_modules/zeppelin-solidity/contracts` folder. You can use the contracts in the library like so:
+## Installing OpenZeppelin
 
-```js
-import 'zeppelin-solidity/contracts/ownership/Ownable.sol';
+After installing either Framework, to install the OpenZeppelin library, run the following in your Solidity project root directory:
+
+```sh
+npm init -y
+npm install -E openzeppelin-solidity
+```
+
+**Note that OpenZeppelin does not currently follow semantic versioning.** You may encounter breaking changes upon a minor version bump. We recommend pinning the version of OpenZeppelin you use, as done by the `-E` (`--save-exact`) option.
+
+After that, you'll get all the library's contracts in the `node_modules/openzeppelin-solidity/contracts` folder. You can use the contracts in the library like so:
+
+```solidity
+import 'openzeppelin-solidity/contracts/ownership/Ownable.sol';
 
 contract MyContract is Ownable {
   ...
 }
 ```
 
+If you are using Embark, you can also import directly from github:
+
+```solidity
+import "github.com/OpenZeppelin/openzeppelin-solidity/contracts/ownership/Ownable.sol#v1.9.0";
+
+contract MyContract is Ownable {
+  ...
+}
+```
 
 ## Security
 OpenZeppelin is meant to provide secure, tested and community-audited code, but please use common sense when doing anything that deals with real money! We take no responsibility for your implementation decisions and any security problem you might experience.
@@ -47,33 +75,16 @@ If you find a security issue, please email [security@openzeppelin.org](mailto:se
 
 Building a distributed application, protocol or organization with OpenZeppelin?
 
-- Read documentation: https://zeppelin-solidity.readthedocs.io/en/latest/
+- Read documentation: https://openzeppelin.org/api/docs/open-zeppelin.html
 
 - Ask for help and follow progress at: https://slack.openzeppelin.org/
 
 Interested in contributing to OpenZeppelin?
 
 - Framework proposal and roadmap: https://medium.com/zeppelin-blog/zeppelin-framework-proposal-and-development-roadmap-fdfa9a3a32ab#.iain47pak
-- Issue tracker: https://github.com/OpenZeppelin/zeppelin-solidity/issues
-- Contribution guidelines: https://github.com/OpenZeppelin/zeppelin-solidity/blob/master/CONTRIBUTING.md
-
-## Collaborating organizations and audits by OpenZeppelin
-- [Golem](https://golem.network/)
-- [Mediachain](http://www.mediachain.io/)
-- [Truffle](http://truffleframework.com/)
-- [Firstblood](https://firstblood.io/)
-- [Rootstock](https://www.rsk.co/)
-- [Consensys](https://consensys.net/)
-- [DigixGlobal](https://www.dgx.io/)
-- [Coinfund](https://coinfund.io/)
-- [DemocracyEarth](https://democracy.earth/)
-- [Signatura](https://signatura.co/)
-- [Ether.camp](http://www.ether.camp/)
-- [Aragon](https://aragon.one/)
-- [Wings](https://wings.ai/)
-
-among others...
-
+- Issue tracker: https://github.com/OpenZeppelin/openzeppelin-solidity/issues
+- Contribution guidelines: https://github.com/OpenZeppelin/openzeppelin-solidity/blob/master/CONTRIBUTING.md
+- Wiki: https://github.com/OpenZeppelin/openzeppelin-solidity/wiki
 
 ## License
-Code released under the [MIT License](https://github.com/OpenZeppelin/zeppelin-solidity/blob/master/LICENSE).
+Code released under the [MIT License](https://github.com/OpenZeppelin/openzeppelin-solidity/blob/master/LICENSE).

contracts/.npmignore

@@ -0,0 +1,2 @@
+mocks
+examples

contracts/AddressUtils.sol

@@ -0,0 +1,29 @@
+pragma solidity ^0.4.23;
+
+
+/**
+ * Utility library of inline functions on addresses
+ */
+library AddressUtils {
+
+  /**
+   * Returns whether the target address is a contract
+   * @dev This function will return false if invoked during the constructor of a contract,
+   *  as the code is not actually created until after the constructor finishes.
+   * @param addr address to check
+   * @return whether the target address is a contract
+   */
+  function isContract(address addr) internal view returns (bool) {
+    uint256 size;
+    // XXX Currently there is no better way to check if there is a contract in an address
+    // than to check the size of the code at that address.
+    // See https://ethereum.stackexchange.com/a/14016/36603
+    // for more details about how this works.
+    // TODO Check this again before the Serenity release, because all addresses will be
+    // contracts then.
+    // solium-disable-next-line security/no-inline-assembly
+    assembly { size := extcodesize(addr) }
+    return size > 0;
+  }
+
+}

contracts/Bounty.sol

@@ -1,8 +1,8 @@
-pragma solidity ^0.4.18;
+pragma solidity ^0.4.23;
 
 
-import './payment/PullPayment.sol';
-import './lifecycle/Destructible.sol';
+import "./payment/PullPayment.sol";
+import "./lifecycle/Destructible.sol";
 
 
 /**
@@ -30,16 +30,10 @@ contract Bounty is PullPayment, Destructible {
   function createTarget() public returns(Target) {
     Target target = Target(deployContract());
     researchers[target] = msg.sender;
-    TargetCreated(target);
+    emit TargetCreated(target);
     return target;
   }
 
-  /**
-   * @dev Internal function to deploy the target contract.
-   * @return A target contract address
-   */
-  function deployContract() internal returns(address);
-
   /**
    * @dev Sends the contract funds to the researcher that proved the contract is broken.
    * @param target contract
@@ -49,10 +43,16 @@ contract Bounty is PullPayment, Destructible {
     require(researcher != 0);
     // Check Target contract invariants
     require(!target.checkInvariant());
-    asyncSend(researcher, this.balance);
+    asyncSend(researcher, address(this).balance);
     claimed = true;
   }
 
+  /**
+   * @dev Internal function to deploy the target contract.
+   * @return A target contract address
+   */
+  function deployContract() internal returns(address);
+
 }
 
 

contracts/DayLimit.sol

@@ -1,73 +0,0 @@
-pragma solidity ^0.4.18;
-
-/**
- * @title DayLimit
- * @dev Base contract that enables methods to be protected by placing a linear limit (specifiable)
- * on a particular resource per calendar day. Is multiowned to allow the limit to be altered.
- */
-contract DayLimit {
-
-  uint256 public dailyLimit;
-  uint256 public spentToday;
-  uint256 public lastDay;
-
-  /**
-   * @dev Constructor that sets the passed value as a dailyLimit.
-   * @param _limit uint256 to represent the daily limit.
-   */
-  function DayLimit(uint256 _limit) public {
-    dailyLimit = _limit;
-    lastDay = today();
-  }
-
-  /**
-   * @dev sets the daily limit. Does not alter the amount already spent today.
-   * @param _newLimit uint256 to represent the new limit.
-   */
-  function _setDailyLimit(uint256 _newLimit) internal {
-    dailyLimit = _newLimit;
-  }
-
-  /**
-   * @dev Resets the amount already spent today.
-   */
-  function _resetSpentToday() internal {
-    spentToday = 0;
-  }
-
-  /**
-   * @dev Checks to see if there is enough resource to spend today. If true, the resource may be expended.
-   * @param _value uint256 representing the amount of resource to spend.
-   * @return A boolean that is True if the resource was spent and false otherwise.
-   */
-  function underLimit(uint256 _value) internal returns (bool) {
-    // reset the spend limit if we're on a different day to last time.
-    if (today() > lastDay) {
-      spentToday = 0;
-      lastDay = today();
-    }
-    // check to see if there's enough left - if so, subtract and return true.
-    // overflow protection                    // dailyLimit check
-    if (spentToday + _value >= spentToday && spentToday + _value <= dailyLimit) {
-      spentToday += _value;
-      return true;
-    }
-    return false;
-  }
-
-  /**
-   * @dev Private function to determine today's index
-   * @return uint256 of today's index.
-   */
-  function today() private view returns (uint256) {
-    return now / 1 days;
-  }
-
-  /**
-   * @dev Simple modifier for daily limit.
-   */
-  modifier limitedDaily(uint256 _value) {
-    require(underLimit(_value));
-    _;
-  }
-}

contracts/ECRecovery.sol

@@ -1,30 +1,41 @@
-pragma solidity ^0.4.18;
+pragma solidity ^0.4.23;
 
 
 /**
  * @title Eliptic curve signature operations
  *
  * @dev Based on https://gist.github.com/axic/5b33912c6f61ae6fd96d6c4a47afde6d
+ *
+ * TODO Remove this library once solidity supports passing a signature to ecrecover.
+ * See https://github.com/ethereum/solidity/issues/864
+ *
  */
 
 library ECRecovery {
 
   /**
-   * @dev Recover signer address from a message by using his signature
+   * @dev Recover signer address from a message by using their signature
    * @param hash bytes32 message, the hash is the signed message. What is recovered is the signer address.
    * @param sig bytes signature, the signature is generated using web3.eth.sign()
    */
-  function recover(bytes32 hash, bytes sig) public pure returns (address) {
+  function recover(bytes32 hash, bytes sig)
+    internal
+    pure
+    returns (address)
+  {
     bytes32 r;
     bytes32 s;
     uint8 v;
 
-    //Check the signature length
+    // Check the signature length
     if (sig.length != 65) {
       return (address(0));
     }
 
     // Divide the signature in r, s and v variables
+    // ecrecover takes the signature parameters, and the only way to get them
+    // currently is to use assembly.
+    // solium-disable-next-line security/no-inline-assembly
     assembly {
       r := mload(add(sig, 32))
       s := mload(add(sig, 64))
@@ -40,8 +51,26 @@ library ECRecovery {
     if (v != 27 && v != 28) {
       return (address(0));
     } else {
+      // solium-disable-next-line arg-overflow
       return ecrecover(hash, v, r, s);
     }
   }
 
+  /**
+   * toEthSignedMessageHash
+   * @dev prefix a bytes32 value with "\x19Ethereum Signed Message:"
+   * @dev and hash the result
+   */
+  function toEthSignedMessageHash(bytes32 hash)
+    internal
+    pure
+    returns (bytes32)
+  {
+    // 32 is the length in bytes of hash,
+    // enforced by the type signature above
+    return keccak256(
+      "\x19Ethereum Signed Message:\n32",
+      hash
+    );
+  }
 }

contracts/LimitBalance.sol

@@ -1,4 +1,4 @@
-pragma solidity ^0.4.18;
+pragma solidity ^0.4.23;
 
 
 /**
@@ -15,7 +15,7 @@ contract LimitBalance {
    * @dev Constructor that sets the passed value as a limit.
    * @param _limit uint256 to represent the limit.
    */
-  function LimitBalance(uint256 _limit) public {
+  constructor(uint256 _limit) public {
     limit = _limit;
   }
 
@@ -23,7 +23,7 @@ contract LimitBalance {
    * @dev Checks if limit was reached. Case true, it throws.
    */
   modifier limitedPayable() {
-    require(this.balance <= limit);
+    require(address(this).balance <= limit);
     _;
 
   }

contracts/MerkleProof.sol

@@ -1,4 +1,5 @@
-pragma solidity ^0.4.18;
+pragma solidity ^0.4.23;
+
 
 /*
  * @title MerkleProof
@@ -13,18 +14,19 @@ library MerkleProof {
    * @param _root Merkle root
    * @param _leaf Leaf of Merkle tree
    */
-  function verifyProof(bytes _proof, bytes32 _root, bytes32 _leaf) public pure returns (bool) {
-    // Check if proof length is a multiple of 32
-    if (_proof.length % 32 != 0) return false;
-
-    bytes32 proofElement;
+  function verifyProof(
+    bytes32[] _proof,
+    bytes32 _root,
+    bytes32 _leaf
+  )
+    internal
+    pure
+    returns (bool)
+  {
     bytes32 computedHash = _leaf;
 
-    for (uint256 i = 32; i <= _proof.length; i += 32) {
-      assembly {
-        // Load the current element of the proof
-        proofElement := mload(add(_proof, i))
-      }
+    for (uint256 i = 0; i < _proof.length; i++) {
+      bytes32 proofElement = _proof[i];
 
       if (computedHash < proofElement) {
         // Hash(current computed hash + current element of the proof)

contracts/ReentrancyGuard.sol

@@ -1,4 +1,5 @@
-pragma solidity ^0.4.18;
+pragma solidity ^0.4.23;
+
 
 /**
  * @title Helps contracts guard agains reentrancy attacks.
@@ -11,7 +12,7 @@ contract ReentrancyGuard {
   /**
    * @dev We use a single lock for the whole contract.
    */
-  bool private reentrancy_lock = false;
+  bool private reentrancyLock = false;
 
   /**
    * @dev Prevents a contract from calling itself, directly or indirectly.
@@ -22,10 +23,10 @@ contract ReentrancyGuard {
    * wrapper marked as `nonReentrant`.
    */
   modifier nonReentrant() {
-    require(!reentrancy_lock);
-    reentrancy_lock = true;
+    require(!reentrancyLock);
+    reentrancyLock = true;
     _;
-    reentrancy_lock = false;
+    reentrancyLock = false;
   }
 
 }

contracts/access/SignatureBouncer.sol

@@ -0,0 +1,91 @@
+pragma solidity ^0.4.23;
+
+import "../ownership/Ownable.sol";
+import "../ownership/rbac/RBAC.sol";
+import "../ECRecovery.sol";
+
+
+/**
+ * @title SignatureBouncer
+ * @author PhABC and Shrugs
+ * @dev Bouncer allows users to submit a signature as a permission to do an action.
+ * @dev If the signature is from one of the authorized bouncer addresses, the signature
+ * @dev is valid. The owner of the contract adds/removes bouncers.
+ * @dev Bouncer addresses can be individual servers signing grants or different
+ * @dev users within a decentralized club that have permission to invite other members.
+ * @dev
+ * @dev This technique is useful for whitelists and airdrops; instead of putting all
+ * @dev valid addresses on-chain, simply sign a grant of the form
+ * @dev keccak256(`:contractAddress` + `:granteeAddress`) using a valid bouncer address.
+ * @dev Then restrict access to your crowdsale/whitelist/airdrop using the
+ * @dev `onlyValidSignature` modifier (or implement your own using isValidSignature).
+ * @dev
+ * @dev See the tests Bouncer.test.js for specific usage examples.
+ */
+contract SignatureBouncer is Ownable, RBAC {
+  using ECRecovery for bytes32;
+
+  string public constant ROLE_BOUNCER = "bouncer";
+
+  /**
+   * @dev requires that a valid signature of a bouncer was provided
+   */
+  modifier onlyValidSignature(bytes _sig)
+  {
+    require(isValidSignature(msg.sender, _sig));
+    _;
+  }
+
+  /**
+   * @dev allows the owner to add additional bouncer addresses
+   */
+  function addBouncer(address _bouncer)
+    onlyOwner
+    public
+  {
+    require(_bouncer != address(0));
+    addRole(_bouncer, ROLE_BOUNCER);
+  }
+
+  /**
+   * @dev allows the owner to remove bouncer addresses
+   */
+  function removeBouncer(address _bouncer)
+    onlyOwner
+    public
+  {
+    require(_bouncer != address(0));
+    removeRole(_bouncer, ROLE_BOUNCER);
+  }
+
+  /**
+   * @dev is the signature of `this + sender` from a bouncer?
+   * @return bool
+   */
+  function isValidSignature(address _address, bytes _sig)
+    internal
+    view
+    returns (bool)
+  {
+    return isValidDataHash(
+      keccak256(address(this), _address),
+      _sig
+    );
+  }
+
+  /**
+   * @dev internal function to convert a hash to an eth signed message
+   * @dev and then recover the signature and check it against the bouncer role
+   * @return bool
+   */
+  function isValidDataHash(bytes32 hash, bytes _sig)
+    internal
+    view
+    returns (bool)
+  {
+    address signer = hash
+      .toEthSignedMessageHash()
+      .recover(_sig);
+    return hasRole(signer, ROLE_BOUNCER);
+  }
+}

contracts/crowdsale/CappedCrowdsale.sol

@@ -1,34 +0,0 @@
-pragma solidity ^0.4.18;
-
-import '../math/SafeMath.sol';
-import './Crowdsale.sol';
-
-/**
- * @title CappedCrowdsale
- * @dev Extension of Crowdsale with a max amount of funds raised
- */
-contract CappedCrowdsale is Crowdsale {
-  using SafeMath for uint256;
-
-  uint256 public cap;
-
-  function CappedCrowdsale(uint256 _cap) public {
-    require(_cap > 0);
-    cap = _cap;
-  }
-
-  // overriding Crowdsale#validPurchase to add extra cap logic
-  // @return true if investors can buy at the moment
-  function validPurchase() internal view returns (bool) {
-    bool withinCap = weiRaised.add(msg.value) <= cap;
-    return super.validPurchase() && withinCap;
-  }
-
-  // overriding Crowdsale#hasEnded to add cap logic
-  // @return true if crowdsale event has ended
-  function hasEnded() public view returns (bool) {
-    bool capReached = weiRaised >= cap;
-    return super.hasEnded() || capReached;
-  }
-
-}

contracts/crowdsale/Crowdsale.sol

@@ -1,106 +1,198 @@
-pragma solidity ^0.4.18;
+pragma solidity ^0.4.23;
+
+import "../token/ERC20/ERC20.sol";
+import "../math/SafeMath.sol";
 
-import '../token/MintableToken.sol';
-import '../math/SafeMath.sol';
 
 /**
  * @title Crowdsale
- * @dev Crowdsale is a base contract for managing a token crowdsale.
- * Crowdsales have a start and end timestamps, where investors can make
- * token purchases and the crowdsale will assign them tokens based
- * on a token per ETH rate. Funds collected are forwarded to a wallet
- * as they arrive.
+ * @dev Crowdsale is a base contract for managing a token crowdsale,
+ * allowing investors to purchase tokens with ether. This contract implements
+ * such functionality in its most fundamental form and can be extended to provide additional
+ * functionality and/or custom behavior.
+ * The external interface represents the basic interface for purchasing tokens, and conform
+ * the base architecture for crowdsales. They are *not* intended to be modified / overriden.
+ * The internal interface conforms the extensible and modifiable surface of crowdsales. Override
+ * the methods to add functionality. Consider using 'super' where appropiate to concatenate
+ * behavior.
  */
 contract Crowdsale {
   using SafeMath for uint256;
 
   // The token being sold
-  MintableToken public token;
+  ERC20 public token;
 
-  // start and end timestamps where investments are allowed (both inclusive)
-  uint256 public startTime;
-  uint256 public endTime;
-
-  // address where funds are collected
+  // Address where funds are collected
   address public wallet;
 
-  // how many token units a buyer gets per wei
+  // How many token units a buyer gets per wei.
+  // The rate is the conversion between wei and the smallest and indivisible token unit.
+  // So, if you are using a rate of 1 with a DetailedERC20 token with 3 decimals called TOK
+  // 1 wei will give you 1 unit, or 0.001 TOK.
   uint256 public rate;
 
-  // amount of raised money in wei
+  // Amount of wei raised
   uint256 public weiRaised;
 
   /**
-   * event for token purchase logging
+   * Event for token purchase logging
    * @param purchaser who paid for the tokens
    * @param beneficiary who got the tokens
    * @param value weis paid for purchase
    * @param amount amount of tokens purchased
    */
-  event TokenPurchase(address indexed purchaser, address indexed beneficiary, uint256 value, uint256 amount);
+  event TokenPurchase(
+    address indexed purchaser,
+    address indexed beneficiary,
+    uint256 value,
+    uint256 amount
+  );
 
-
-  function Crowdsale(uint256 _startTime, uint256 _endTime, uint256 _rate, address _wallet) public {
-    require(_startTime >= now);
-    require(_endTime >= _startTime);
+  /**
+   * @param _rate Number of token units a buyer gets per wei
+   * @param _wallet Address where collected funds will be forwarded to
+   * @param _token Address of the token being sold
+   */
+  constructor(uint256 _rate, address _wallet, ERC20 _token) public {
     require(_rate > 0);
     require(_wallet != address(0));
+    require(_token != address(0));
 
-    token = createTokenContract();
-    startTime = _startTime;
-    endTime = _endTime;
     rate = _rate;
     wallet = _wallet;
+    token = _token;
   }
 
-  // creates the token to be sold.
-  // override this method to have crowdsale of a specific mintable token.
-  function createTokenContract() internal returns (MintableToken) {
-    return new MintableToken();
-  }
+  // -----------------------------------------
+  // Crowdsale external interface
+  // -----------------------------------------
 
-
-  // fallback function can be used to buy tokens
+  /**
+   * @dev fallback function ***DO NOT OVERRIDE***
+   */
   function () external payable {
     buyTokens(msg.sender);
   }
 
-  // low level token purchase function
-  function buyTokens(address beneficiary) public payable {
-    require(beneficiary != address(0));
-    require(validPurchase());
+  /**
+   * @dev low level token purchase ***DO NOT OVERRIDE***
+   * @param _beneficiary Address performing the token purchase
+   */
+  function buyTokens(address _beneficiary) public payable {
 
     uint256 weiAmount = msg.value;
+    _preValidatePurchase(_beneficiary, weiAmount);
 
     // calculate token amount to be created
-    uint256 tokens = weiAmount.mul(rate);
+    uint256 tokens = _getTokenAmount(weiAmount);
 
     // update state
     weiRaised = weiRaised.add(weiAmount);
 
-    token.mint(beneficiary, tokens);
-    TokenPurchase(msg.sender, beneficiary, weiAmount, tokens);
+    _processPurchase(_beneficiary, tokens);
+    emit TokenPurchase(
+      msg.sender,
+      _beneficiary,
+      weiAmount,
+      tokens
+    );
 
-    forwardFunds();
+    _updatePurchasingState(_beneficiary, weiAmount);
+
+    _forwardFunds();
+    _postValidatePurchase(_beneficiary, weiAmount);
   }
 
-  // send ether to the fund collection wallet
-  // override to create custom fund forwarding mechanisms
-  function forwardFunds() internal {
+  // -----------------------------------------
+  // Internal interface (extensible)
+  // -----------------------------------------
+
+  /**
+   * @dev Validation of an incoming purchase. Use require statements to revert state when conditions are not met. Use super to concatenate validations.
+   * @param _beneficiary Address performing the token purchase
+   * @param _weiAmount Value in wei involved in the purchase
+   */
+  function _preValidatePurchase(
+    address _beneficiary,
+    uint256 _weiAmount
+  )
+    internal
+  {
+    require(_beneficiary != address(0));
+    require(_weiAmount != 0);
+  }
+
+  /**
+   * @dev Validation of an executed purchase. Observe state and use revert statements to undo rollback when valid conditions are not met.
+   * @param _beneficiary Address performing the token purchase
+   * @param _weiAmount Value in wei involved in the purchase
+   */
+  function _postValidatePurchase(
+    address _beneficiary,
+    uint256 _weiAmount
+  )
+    internal
+  {
+    // optional override
+  }
+
+  /**
+   * @dev Source of tokens. Override this method to modify the way in which the crowdsale ultimately gets and sends its tokens.
+   * @param _beneficiary Address performing the token purchase
+   * @param _tokenAmount Number of tokens to be emitted
+   */
+  function _deliverTokens(
+    address _beneficiary,
+    uint256 _tokenAmount
+  )
+    internal
+  {
+    token.transfer(_beneficiary, _tokenAmount);
+  }
+
+  /**
+   * @dev Executed when a purchase has been validated and is ready to be executed. Not necessarily emits/sends tokens.
+   * @param _beneficiary Address receiving the tokens
+   * @param _tokenAmount Number of tokens to be purchased
+   */
+  function _processPurchase(
+    address _beneficiary,
+    uint256 _tokenAmount
+  )
+    internal
+  {
+    _deliverTokens(_beneficiary, _tokenAmount);
+  }
+
+  /**
+   * @dev Override for extensions that require an internal state to check for validity (current user contributions, etc.)
+   * @param _beneficiary Address receiving the tokens
+   * @param _weiAmount Value in wei involved in the purchase
+   */
+  function _updatePurchasingState(
+    address _beneficiary,
+    uint256 _weiAmount
+  )
+    internal
+  {
+    // optional override
+  }
+
+  /**
+   * @dev Override to extend the way in which ether is converted to tokens.
+   * @param _weiAmount Value in wei to be converted into tokens
+   * @return Number of tokens that can be purchased with the specified _weiAmount
+   */
+  function _getTokenAmount(uint256 _weiAmount)
+    internal view returns (uint256)
+  {
+    return _weiAmount.mul(rate);
+  }
+
+  /**
+   * @dev Determines how ETH is stored/forwarded on purchases.
+   */
+  function _forwardFunds() internal {
     wallet.transfer(msg.value);
   }
-
-  // @return true if the transaction can buy tokens
-  function validPurchase() internal view returns (bool) {
-    bool withinPeriod = now >= startTime && now <= endTime;
-    bool nonZeroPurchase = msg.value != 0;
-    return withinPeriod && nonZeroPurchase;
-  }
-
-  // @return true if crowdsale event has ended
-  function hasEnded() public view returns (bool) {
-    return now > endTime;
-  }
-
-
 }

contracts/crowdsale/distribution/FinalizableCrowdsale.sol

@@ -1,15 +1,16 @@
-pragma solidity ^0.4.18;
+pragma solidity ^0.4.23;
+
+import "../../math/SafeMath.sol";
+import "../../ownership/Ownable.sol";
+import "../validation/TimedCrowdsale.sol";
 
-import '../math/SafeMath.sol';
-import '../ownership/Ownable.sol';
-import './Crowdsale.sol';
 
 /**
  * @title FinalizableCrowdsale
  * @dev Extension of Crowdsale where an owner can do extra work
  * after finishing.
  */
-contract FinalizableCrowdsale is Crowdsale, Ownable {
+contract FinalizableCrowdsale is TimedCrowdsale, Ownable {
   using SafeMath for uint256;
 
   bool public isFinalized = false;
@@ -22,10 +23,10 @@ contract FinalizableCrowdsale is Crowdsale, Ownable {
    */
   function finalize() onlyOwner public {
     require(!isFinalized);
-    require(hasEnded());
+    require(hasClosed());
 
     finalization();
-    Finalized();
+    emit Finalized();
 
     isFinalized = true;
   }
@@ -37,4 +38,5 @@ contract FinalizableCrowdsale is Crowdsale, Ownable {
    */
   function finalization() internal {
   }
+
 }

contracts/crowdsale/distribution/PostDeliveryCrowdsale.sol

@@ -0,0 +1,42 @@
+pragma solidity ^0.4.23;
+
+import "../validation/TimedCrowdsale.sol";
+import "../../token/ERC20/ERC20.sol";
+import "../../math/SafeMath.sol";
+
+
+/**
+ * @title PostDeliveryCrowdsale
+ * @dev Crowdsale that locks tokens from withdrawal until it ends.
+ */
+contract PostDeliveryCrowdsale is TimedCrowdsale {
+  using SafeMath for uint256;
+
+  mapping(address => uint256) public balances;
+
+  /**
+   * @dev Withdraw tokens only after crowdsale ends.
+   */
+  function withdrawTokens() public {
+    require(hasClosed());
+    uint256 amount = balances[msg.sender];
+    require(amount > 0);
+    balances[msg.sender] = 0;
+    _deliverTokens(msg.sender, amount);
+  }
+
+  /**
+   * @dev Overrides parent by storing balances instead of issuing tokens right away.
+   * @param _beneficiary Token purchaser
+   * @param _tokenAmount Amount of tokens purchased
+   */
+  function _processPurchase(
+    address _beneficiary,
+    uint256 _tokenAmount
+  )
+    internal
+  {
+    balances[_beneficiary] = balances[_beneficiary].add(_tokenAmount);
+  }
+
+}

contracts/crowdsale/distribution/RefundableCrowdsale.sol

@@ -1,9 +1,9 @@
-pragma solidity ^0.4.18;
+pragma solidity ^0.4.23;
 
 
-import '../math/SafeMath.sol';
-import './FinalizableCrowdsale.sol';
-import './RefundVault.sol';
+import "../../math/SafeMath.sol";
+import "./FinalizableCrowdsale.sol";
+import "./utils/RefundVault.sol";
 
 
 /**
@@ -21,20 +21,19 @@ contract RefundableCrowdsale is FinalizableCrowdsale {
   // refund vault used to hold funds while crowdsale is running
   RefundVault public vault;
 
-  function RefundableCrowdsale(uint256 _goal) public {
+  /**
+   * @dev Constructor, creates RefundVault.
+   * @param _goal Funding goal
+   */
+  constructor(uint256 _goal) public {
     require(_goal > 0);
     vault = new RefundVault(wallet);
     goal = _goal;
   }
 
-  // We're overriding the fund forwarding from Crowdsale.
-  // In addition to sending the funds, we want to call
-  // the RefundVault deposit function
-  function forwardFunds() internal {
-    vault.deposit.value(msg.value)(msg.sender);
-  }
-
-  // if crowdsale is unsuccessful, investors can claim refunds here
+  /**
+   * @dev Investors can claim refunds here if crowdsale is unsuccessful
+   */
   function claimRefund() public {
     require(isFinalized);
     require(!goalReached());
@@ -42,7 +41,17 @@ contract RefundableCrowdsale is FinalizableCrowdsale {
     vault.refund(msg.sender);
   }
 
-  // vault finalization task, called when owner calls finalize()
+  /**
+   * @dev Checks whether funding goal was reached.
+   * @return Whether funding goal was reached
+   */
+  function goalReached() public view returns (bool) {
+    return weiRaised >= goal;
+  }
+
+  /**
+   * @dev vault finalization task, called when owner calls finalize()
+   */
   function finalization() internal {
     if (goalReached()) {
       vault.close();
@@ -53,8 +62,11 @@ contract RefundableCrowdsale is FinalizableCrowdsale {
     super.finalization();
   }
 
-  function goalReached() public view returns (bool) {
-    return weiRaised >= goal;
+  /**
+   * @dev Overrides Crowdsale fund forwarding, sending funds to vault.
+   */
+  function _forwardFunds() internal {
+    vault.deposit.value(msg.value)(msg.sender);
   }
 
 }

contracts/crowdsale/distribution/utils/RefundVault.sol

@@ -1,7 +1,8 @@
-pragma solidity ^0.4.18;
+pragma solidity ^0.4.23;
+
+import "../../../math/SafeMath.sol";
+import "../../../ownership/Ownable.sol";
 
-import '../math/SafeMath.sol';
-import '../ownership/Ownable.sol';
 
 /**
  * @title RefundVault
@@ -22,12 +23,18 @@ contract RefundVault is Ownable {
   event RefundsEnabled();
   event Refunded(address indexed beneficiary, uint256 weiAmount);
 
-  function RefundVault(address _wallet) public {
+  /**
+   * @param _wallet Vault address
+   */
+  constructor(address _wallet) public {
     require(_wallet != address(0));
     wallet = _wallet;
     state = State.Active;
   }
 
+  /**
+   * @param investor Investor address
+   */
   function deposit(address investor) onlyOwner public payable {
     require(state == State.Active);
     deposited[investor] = deposited[investor].add(msg.value);
@@ -36,21 +43,24 @@ contract RefundVault is Ownable {
   function close() onlyOwner public {
     require(state == State.Active);
     state = State.Closed;
-    Closed();
-    wallet.transfer(this.balance);
+    emit Closed();
+    wallet.transfer(address(this).balance);
   }
 
   function enableRefunds() onlyOwner public {
     require(state == State.Active);
     state = State.Refunding;
-    RefundsEnabled();
+    emit RefundsEnabled();
   }
 
+  /**
+   * @param investor Investor address
+   */
   function refund(address investor) public {
     require(state == State.Refunding);
     uint256 depositedValue = deposited[investor];
     deposited[investor] = 0;
     investor.transfer(depositedValue);
-    Refunded(investor, depositedValue);
+    emit Refunded(investor, depositedValue);
   }
 }

contracts/crowdsale/emission/AllowanceCrowdsale.sol

@@ -0,0 +1,47 @@
+pragma solidity ^0.4.23;
+
+import "../Crowdsale.sol";
+import "../../token/ERC20/ERC20.sol";
+import "../../math/SafeMath.sol";
+
+
+/**
+ * @title AllowanceCrowdsale
+ * @dev Extension of Crowdsale where tokens are held by a wallet, which approves an allowance to the crowdsale.
+ */
+contract AllowanceCrowdsale is Crowdsale {
+  using SafeMath for uint256;
+
+  address public tokenWallet;
+
+  /**
+   * @dev Constructor, takes token wallet address.
+   * @param _tokenWallet Address holding the tokens, which has approved allowance to the crowdsale
+   */
+  constructor(address _tokenWallet) public {
+    require(_tokenWallet != address(0));
+    tokenWallet = _tokenWallet;
+  }
+
+  /**
+   * @dev Checks the amount of tokens left in the allowance.
+   * @return Amount of tokens left in the allowance
+   */
+  function remainingTokens() public view returns (uint256) {
+    return token.allowance(tokenWallet, this);
+  }
+
+  /**
+   * @dev Overrides parent behavior by transferring tokens from wallet.
+   * @param _beneficiary Token purchaser
+   * @param _tokenAmount Amount of tokens purchased
+   */
+  function _deliverTokens(
+    address _beneficiary,
+    uint256 _tokenAmount
+  )
+    internal
+  {
+    token.transferFrom(tokenWallet, _beneficiary, _tokenAmount);
+  }
+}

contracts/crowdsale/emission/MintedCrowdsale.sol

@@ -0,0 +1,27 @@
+pragma solidity ^0.4.23;
+
+import "../Crowdsale.sol";
+import "../../token/ERC20/MintableToken.sol";
+
+
+/**
+ * @title MintedCrowdsale
+ * @dev Extension of Crowdsale contract whose tokens are minted in each purchase.
+ * Token ownership should be transferred to MintedCrowdsale for minting.
+ */
+contract MintedCrowdsale is Crowdsale {
+
+  /**
+   * @dev Overrides delivery by minting tokens upon purchase.
+   * @param _beneficiary Token purchaser
+   * @param _tokenAmount Number of tokens to be minted
+   */
+  function _deliverTokens(
+    address _beneficiary,
+    uint256 _tokenAmount
+  )
+    internal
+  {
+    require(MintableToken(token).mint(_beneficiary, _tokenAmount));
+  }
+}

contracts/crowdsale/price/IncreasingPriceCrowdsale.sol

@@ -0,0 +1,56 @@
+pragma solidity ^0.4.23;
+
+import "../validation/TimedCrowdsale.sol";
+import "../../math/SafeMath.sol";
+
+
+/**
+ * @title IncreasingPriceCrowdsale
+ * @dev Extension of Crowdsale contract that increases the price of tokens linearly in time.
+ * Note that what should be provided to the constructor is the initial and final _rates_, that is,
+ * the amount of tokens per wei contributed. Thus, the initial rate must be greater than the final rate.
+ */
+contract IncreasingPriceCrowdsale is TimedCrowdsale {
+  using SafeMath for uint256;
+
+  uint256 public initialRate;
+  uint256 public finalRate;
+
+  /**
+   * @dev Constructor, takes intial and final rates of tokens received per wei contributed.
+   * @param _initialRate Number of tokens a buyer gets per wei at the start of the crowdsale
+   * @param _finalRate Number of tokens a buyer gets per wei at the end of the crowdsale
+   */
+  constructor(uint256 _initialRate, uint256 _finalRate) public {
+    require(_initialRate >= _finalRate);
+    require(_finalRate > 0);
+    initialRate = _initialRate;
+    finalRate = _finalRate;
+  }
+
+  /**
+   * @dev Returns the rate of tokens per wei at the present time.
+   * Note that, as price _increases_ with time, the rate _decreases_.
+   * @return The number of tokens a buyer gets per wei at a given time
+   */
+  function getCurrentRate() public view returns (uint256) {
+    // solium-disable-next-line security/no-block-members
+    uint256 elapsedTime = block.timestamp.sub(openingTime);
+    uint256 timeRange = closingTime.sub(openingTime);
+    uint256 rateRange = initialRate.sub(finalRate);
+    return initialRate.sub(elapsedTime.mul(rateRange).div(timeRange));
+  }
+
+  /**
+   * @dev Overrides parent method taking into account variable rate.
+   * @param _weiAmount The value in wei to be converted into tokens
+   * @return The number of tokens _weiAmount wei will buy at present time
+   */
+  function _getTokenAmount(uint256 _weiAmount)
+    internal view returns (uint256)
+  {
+    uint256 currentRate = getCurrentRate();
+    return currentRate.mul(_weiAmount);
+  }
+
+}

contracts/crowdsale/validation/CappedCrowdsale.sol

@@ -0,0 +1,48 @@
+pragma solidity ^0.4.23;
+
+import "../../math/SafeMath.sol";
+import "../Crowdsale.sol";
+
+
+/**
+ * @title CappedCrowdsale
+ * @dev Crowdsale with a limit for total contributions.
+ */
+contract CappedCrowdsale is Crowdsale {
+  using SafeMath for uint256;
+
+  uint256 public cap;
+
+  /**
+   * @dev Constructor, takes maximum amount of wei accepted in the crowdsale.
+   * @param _cap Max amount of wei to be contributed
+   */
+  constructor(uint256 _cap) public {
+    require(_cap > 0);
+    cap = _cap;
+  }
+
+  /**
+   * @dev Checks whether the cap has been reached.
+   * @return Whether the cap was reached
+   */
+  function capReached() public view returns (bool) {
+    return weiRaised >= cap;
+  }
+
+  /**
+   * @dev Extend parent behavior requiring purchase to respect the funding cap.
+   * @param _beneficiary Token purchaser
+   * @param _weiAmount Amount of wei contributed
+   */
+  function _preValidatePurchase(
+    address _beneficiary,
+    uint256 _weiAmount
+  )
+    internal
+  {
+    super._preValidatePurchase(_beneficiary, _weiAmount);
+    require(weiRaised.add(_weiAmount) <= cap);
+  }
+
+}

contracts/crowdsale/validation/IndividuallyCappedCrowdsale.sol

@@ -0,0 +1,94 @@
+pragma solidity ^0.4.23;
+
+import "../../math/SafeMath.sol";
+import "../Crowdsale.sol";
+import "../../ownership/Ownable.sol";
+
+
+/**
+ * @title IndividuallyCappedCrowdsale
+ * @dev Crowdsale with per-user caps.
+ */
+contract IndividuallyCappedCrowdsale is Crowdsale, Ownable {
+  using SafeMath for uint256;
+
+  mapping(address => uint256) public contributions;
+  mapping(address => uint256) public caps;
+
+  /**
+   * @dev Sets a specific user's maximum contribution.
+   * @param _beneficiary Address to be capped
+   * @param _cap Wei limit for individual contribution
+   */
+  function setUserCap(address _beneficiary, uint256 _cap) external onlyOwner {
+    caps[_beneficiary] = _cap;
+  }
+
+  /**
+   * @dev Sets a group of users' maximum contribution.
+   * @param _beneficiaries List of addresses to be capped
+   * @param _cap Wei limit for individual contribution
+   */
+  function setGroupCap(
+    address[] _beneficiaries,
+    uint256 _cap
+  )
+    external
+    onlyOwner
+  {
+    for (uint256 i = 0; i < _beneficiaries.length; i++) {
+      caps[_beneficiaries[i]] = _cap;
+    }
+  }
+
+  /**
+   * @dev Returns the cap of a specific user.
+   * @param _beneficiary Address whose cap is to be checked
+   * @return Current cap for individual user
+   */
+  function getUserCap(address _beneficiary) public view returns (uint256) {
+    return caps[_beneficiary];
+  }
+
+  /**
+   * @dev Returns the amount contributed so far by a sepecific user.
+   * @param _beneficiary Address of contributor
+   * @return User contribution so far
+   */
+  function getUserContribution(address _beneficiary)
+    public view returns (uint256)
+  {
+    return contributions[_beneficiary];
+  }
+
+  /**
+   * @dev Extend parent behavior requiring purchase to respect the user's funding cap.
+   * @param _beneficiary Token purchaser
+   * @param _weiAmount Amount of wei contributed
+   */
+  function _preValidatePurchase(
+    address _beneficiary,
+    uint256 _weiAmount
+  )
+    internal
+  {
+    super._preValidatePurchase(_beneficiary, _weiAmount);
+    require(contributions[_beneficiary].add(_weiAmount) <= caps[_beneficiary]);
+  }
+
+  /**
+   * @dev Extend parent behavior to update user contributions
+   * @param _beneficiary Token purchaser
+   * @param _weiAmount Amount of wei contributed
+   */
+  function _updatePurchasingState(
+    address _beneficiary,
+    uint256 _weiAmount
+  )
+    internal
+  {
+    super._updatePurchasingState(_beneficiary, _weiAmount);
+    contributions[_beneficiary] = contributions[_beneficiary].add(_weiAmount);
+  }
+
+}

contracts/crowdsale/validation/TimedCrowdsale.sol

@@ -0,0 +1,64 @@
+pragma solidity ^0.4.23;
+
+import "../../math/SafeMath.sol";
+import "../Crowdsale.sol";
+
+
+/**
+ * @title TimedCrowdsale
+ * @dev Crowdsale accepting contributions only within a time frame.
+ */
+contract TimedCrowdsale is Crowdsale {
+  using SafeMath for uint256;
+
+  uint256 public openingTime;
+  uint256 public closingTime;
+
+  /**
+   * @dev Reverts if not in crowdsale time range.
+   */
+  modifier onlyWhileOpen {
+    // solium-disable-next-line security/no-block-members
+    require(block.timestamp >= openingTime && block.timestamp <= closingTime);
+    _;
+  }
+
+  /**
+   * @dev Constructor, takes crowdsale opening and closing times.
+   * @param _openingTime Crowdsale opening time
+   * @param _closingTime Crowdsale closing time
+   */
+  constructor(uint256 _openingTime, uint256 _closingTime) public {
+    // solium-disable-next-line security/no-block-members
+    require(_openingTime >= block.timestamp);
+    require(_closingTime >= _openingTime);
+
+    openingTime = _openingTime;
+    closingTime = _closingTime;
+  }
+
+  /**
+   * @dev Checks whether the period in which the crowdsale is open has already elapsed.
+   * @return Whether crowdsale period has elapsed
+   */
+  function hasClosed() public view returns (bool) {
+    // solium-disable-next-line security/no-block-members
+    return block.timestamp > closingTime;
+  }
+
+  /**
+   * @dev Extend parent behavior requiring to be within contributing period
+   * @param _beneficiary Token purchaser
+   * @param _weiAmount Amount of wei contributed
+   */
+  function _preValidatePurchase(
+    address _beneficiary,
+    uint256 _weiAmount
+  )
+    internal
+    onlyWhileOpen
+  {
+    super._preValidatePurchase(_beneficiary, _weiAmount);
+  }
+
+}

contracts/crowdsale/validation/WhitelistedCrowdsale.sol

@@ -0,0 +1,64 @@
+pragma solidity ^0.4.23;
+
+import "../Crowdsale.sol";
+import "../../ownership/Ownable.sol";
+
+
+/**
+ * @title WhitelistedCrowdsale
+ * @dev Crowdsale in which only whitelisted users can contribute.
+ */
+contract WhitelistedCrowdsale is Crowdsale, Ownable {
+
+  mapping(address => bool) public whitelist;
+
+  /**
+   * @dev Reverts if beneficiary is not whitelisted. Can be used when extending this contract.
+   */
+  modifier isWhitelisted(address _beneficiary) {
+    require(whitelist[_beneficiary]);
+    _;
+  }
+
+  /**
+   * @dev Adds single address to whitelist.
+   * @param _beneficiary Address to be added to the whitelist
+   */
+  function addToWhitelist(address _beneficiary) external onlyOwner {
+    whitelist[_beneficiary] = true;
+  }
+
+  /**
+   * @dev Adds list of addresses to whitelist. Not overloaded due to limitations with truffle testing.
+   * @param _beneficiaries Addresses to be added to the whitelist
+   */
+  function addManyToWhitelist(address[] _beneficiaries) external onlyOwner {
+    for (uint256 i = 0; i < _beneficiaries.length; i++) {
+      whitelist[_beneficiaries[i]] = true;
+    }
+  }
+
+  /**
+   * @dev Removes single address from whitelist.
+   * @param _beneficiary Address to be removed to the whitelist
+   */
+  function removeFromWhitelist(address _beneficiary) external onlyOwner {
+    whitelist[_beneficiary] = false;
+  }
+
+  /**
+   * @dev Extend parent behavior requiring beneficiary to be in whitelist.
+   * @param _beneficiary Token beneficiary
+   * @param _weiAmount Amount of wei contributed
+   */
+  function _preValidatePurchase(
+    address _beneficiary,
+    uint256 _weiAmount
+  )
+    internal
+    isWhitelisted(_beneficiary)
+  {
+    super._preValidatePurchase(_beneficiary, _weiAmount);
+  }
+
+}

contracts/examples/RBACWithAdmin.sol

@@ -0,0 +1,67 @@
+pragma solidity ^0.4.23;
+
+import "../ownership/rbac/RBAC.sol";
+
+
+/**
+ * @title RBACWithAdmin
+ * @author Matt Condon (@Shrugs)
+ * @dev It's recommended that you define constants in the contract,
+ * @dev like ROLE_ADMIN below, to avoid typos.
+ * @dev
+ * @dev NOTE: RBACWithAdmin is probably too expansive and powerful for your
+ * @dev  application; an admin is actually able to change any address to any role
+ * @dev  which is a very large API surface. It's recommended that you follow a strategy
+ * @dev  of strictly defining the abilities of your roles
+ * @dev  and the API-surface of your contract.
+ * @dev  This is just an example for example's sake.
+ */
+contract RBACWithAdmin is RBAC {
+  /**
+   * A constant role name for indicating admins.
+   */
+  string public constant ROLE_ADMIN = "admin";
+
+  /**
+   * @dev modifier to scope access to admins
+   * // reverts
+   */
+  modifier onlyAdmin()
+  {
+    checkRole(msg.sender, ROLE_ADMIN);
+    _;
+  }
+
+  /**
+   * @dev constructor. Sets msg.sender as admin by default
+   */
+  constructor()
+    public
+  {
+    addRole(msg.sender, ROLE_ADMIN);
+  }
+
+  /**
+   * @dev add a role to an address
+   * @param addr address
+   * @param roleName the name of the role
+   */
+  function adminAddRole(address addr, string roleName)
+    onlyAdmin
+    public
+  {
+    addRole(addr, roleName);
+  }
+
+  /**
+   * @dev remove a role from an address
+   * @param addr address
+   * @param roleName the name of the role
+   */
+  function adminRemoveRole(address addr, string roleName)
+    onlyAdmin
+    public
+  {
+    removeRole(addr, roleName);
+  }
+}

contracts/examples/SampleCrowdsale.sol

@@ -1,8 +1,10 @@
-pragma solidity ^0.4.18;
+pragma solidity ^0.4.23;
+
+import "../crowdsale/validation/CappedCrowdsale.sol";
+import "../crowdsale/distribution/RefundableCrowdsale.sol";
+import "../crowdsale/emission/MintedCrowdsale.sol";
+import "../token/ERC20/MintableToken.sol";
 
-import "../crowdsale/CappedCrowdsale.sol";
-import "../crowdsale/RefundableCrowdsale.sol";
-import "../token/MintableToken.sol";
 
 /**
  * @title SampleCrowdsaleToken
@@ -11,12 +13,14 @@ import "../token/MintableToken.sol";
  */
 contract SampleCrowdsaleToken is MintableToken {
 
+  // solium-disable-next-line uppercase
   string public constant name = "Sample Crowdsale Token";
-  string public constant symbol = "SCT";
-  uint8 public constant decimals = 18;
+  string public constant symbol = "SCT"; // solium-disable-line uppercase
+  uint8 public constant decimals = 18; // solium-disable-line uppercase
 
 }
 
+
 /**
  * @title SampleCrowdsale
  * @dev This is an example of a fully fledged crowdsale.
@@ -28,21 +32,30 @@ contract SampleCrowdsaleToken is MintableToken {
  * After adding multiple features it's good practice to run integration tests
  * to ensure that subcontracts works together as intended.
  */
-contract SampleCrowdsale is CappedCrowdsale, RefundableCrowdsale {
+// XXX There doesn't seem to be a way to split this line that keeps solium
+// happy. See:
+// https://github.com/duaraghav8/Solium/issues/205
+// --elopio - 2018-05-10
+// solium-disable-next-line max-len
+contract SampleCrowdsale is CappedCrowdsale, RefundableCrowdsale, MintedCrowdsale {
 
-  function SampleCrowdsale(uint256 _startTime, uint256 _endTime, uint256 _rate, uint256 _goal, uint256 _cap, address _wallet) public
+  constructor(
+    uint256 _openingTime,
+    uint256 _closingTime,
+    uint256 _rate,
+    address _wallet,
+    uint256 _cap,
+    MintableToken _token,
+    uint256 _goal
+  )
+    public
+    Crowdsale(_rate, _wallet, _token)
     CappedCrowdsale(_cap)
-    FinalizableCrowdsale()
+    TimedCrowdsale(_openingTime, _closingTime)
     RefundableCrowdsale(_goal)
-    Crowdsale(_startTime, _endTime, _rate, _wallet)
   {
     //As goal needs to be met for a successful crowdsale
     //the value needs to less or equal than a cap which is limit for accepted funds
     require(_goal <= _cap);
   }
-
-  function createTokenContract() internal returns (MintableToken) {
-    return new SampleCrowdsaleToken();
-  }
-
 }

contracts/examples/SimpleSavingsWallet.sol

@@ -0,0 +1,40 @@
+pragma solidity ^0.4.23;
+
+import "../ownership/Heritable.sol";
+
+
+/**
+ * @title SimpleSavingsWallet
+ * @dev Simplest form of savings wallet whose ownership can be claimed by a heir
+ * if owner dies.
+ * In this example, we take a very simple savings wallet providing two operations
+ * (to send and receive funds) and extend its capabilities by making it Heritable.
+ * The account that creates the contract is set as owner, who has the authority to
+ * choose an heir account. Heir account can reclaim the contract ownership in the
+ * case that the owner dies.
+ */
+contract SimpleSavingsWallet is Heritable {
+
+  event Sent(address indexed payee, uint256 amount, uint256 balance);
+  event Received(address indexed payer, uint256 amount, uint256 balance);
+
+
+  constructor(uint256 _heartbeatTimeout) Heritable(_heartbeatTimeout) public {}
+
+  /**
+   * @dev wallet can receive funds.
+   */
+  function () public payable {
+    emit Received(msg.sender, msg.value, address(this).balance);
+  }
+
+  /**
+   * @dev wallet can send funds
+   */
+  function sendTo(address payee, uint256 amount) public onlyOwner {
+    require(payee != 0 && payee != address(this));
+    require(amount > 0);
+    payee.transfer(amount);
+    emit Sent(payee, amount, address(this).balance);
+  }
+}

contracts/examples/SimpleToken.sol

@@ -1,7 +1,7 @@
-pragma solidity ^0.4.18;
+pragma solidity ^0.4.23;
 
 
-import "../token/StandardToken.sol";
+import "../token/ERC20/StandardToken.sol";
 
 
 /**
@@ -12,18 +12,19 @@ import "../token/StandardToken.sol";
  */
 contract SimpleToken is StandardToken {
 
-  string public constant name = "SimpleToken";
-  string public constant symbol = "SIM";
-  uint8 public constant decimals = 18;
+  string public constant name = "SimpleToken"; // solium-disable-line uppercase
+  string public constant symbol = "SIM"; // solium-disable-line uppercase
+  uint8 public constant decimals = 18; // solium-disable-line uppercase
 
   uint256 public constant INITIAL_SUPPLY = 10000 * (10 ** uint256(decimals));
 
   /**
    * @dev Constructor that gives msg.sender all of existing tokens.
    */
-  function SimpleToken() public {
-    totalSupply = INITIAL_SUPPLY;
+  constructor() public {
+    totalSupply_ = INITIAL_SUPPLY;
     balances[msg.sender] = INITIAL_SUPPLY;
+    emit Transfer(0x0, msg.sender, INITIAL_SUPPLY);
   }
 
 }

contracts/lifecycle/Destructible.sol

@@ -1,4 +1,4 @@
-pragma solidity ^0.4.18;
+pragma solidity ^0.4.23;
 
 
 import "../ownership/Ownable.sol";
@@ -10,7 +10,7 @@ import "../ownership/Ownable.sol";
  */
 contract Destructible is Ownable {
 
-  function Destructible() public payable { }
+  constructor() public payable { }
 
   /**
    * @dev Transfers the current balance to the owner and terminates the contract.

contracts/lifecycle/Migrations.sol

@@ -1,21 +0,0 @@
-pragma solidity ^0.4.18;
-
-
-import '../ownership/Ownable.sol';
-
-/**
- * @title Migrations
- * @dev This is a truffle contract, needed for truffle integration, not meant for use by Zeppelin users.
- */
-contract Migrations is Ownable {
-  uint256 public lastCompletedMigration;
-
-  function setCompleted(uint256 completed) onlyOwner public {
-    lastCompletedMigration = completed;
-  }
-
-  function upgrade(address newAddress) onlyOwner public {
-    Migrations upgraded = Migrations(newAddress);
-    upgraded.setCompleted(lastCompletedMigration);
-  }
-}

contracts/lifecycle/Pausable.sol

@@ -1,4 +1,4 @@
-pragma solidity ^0.4.18;
+pragma solidity ^0.4.23;
 
 
 import "../ownership/Ownable.sol";
@@ -36,7 +36,7 @@ contract Pausable is Ownable {
    */
   function pause() onlyOwner whenNotPaused public {
     paused = true;
-    Pause();
+    emit Pause();
   }
 
   /**
@@ -44,6 +44,6 @@ contract Pausable is Ownable {
    */
   function unpause() onlyOwner whenPaused public {
     paused = false;
-    Unpause();
+    emit Unpause();
   }
 }

contracts/lifecycle/TokenDestructible.sol

@@ -1,8 +1,8 @@
-pragma solidity ^0.4.18;
-
+pragma solidity ^0.4.23;
 
 import "../ownership/Ownable.sol";
-import "../token/ERC20Basic.sol";
+import "../token/ERC20/ERC20Basic.sol";
+
 
 /**
  * @title TokenDestructible:
@@ -12,7 +12,7 @@ import "../token/ERC20Basic.sol";
  */
 contract TokenDestructible is Ownable {
 
-  function TokenDestructible() public payable { }
+  constructor() public payable { }
 
   /**
    * @notice Terminate contract and refund to owner
@@ -24,7 +24,7 @@ contract TokenDestructible is Ownable {
   function destroy(address[] tokens) onlyOwner public {
 
     // Transfer tokens to owner
-    for(uint256 i = 0; i < tokens.length; i++) {
+    for (uint256 i = 0; i < tokens.length; i++) {
       ERC20Basic token = ERC20Basic(tokens[i]);
       uint256 balance = token.balanceOf(this);
       token.transfer(owner, balance);

contracts/math/Math.sol

@@ -1,10 +1,10 @@
-pragma solidity ^0.4.18;
+pragma solidity ^0.4.23;
+
 
 /**
  * @title Math
  * @dev Assorted math operations
  */
-
 library Math {
   function max64(uint64 a, uint64 b) internal pure returns (uint64) {
     return a >= b ? a : b;

contracts/math/SafeMath.sol

@@ -1,4 +1,4 @@
-pragma solidity ^0.4.18;
+pragma solidity ^0.4.23;
 
 
 /**
@@ -6,29 +6,46 @@ pragma solidity ^0.4.18;
  * @dev Math operations with safety checks that throw on error
  */
 library SafeMath {
-  function mul(uint256 a, uint256 b) internal pure returns (uint256) {
+
+  /**
+  * @dev Multiplies two numbers, throws on overflow.
+  */
+  function mul(uint256 a, uint256 b) internal pure returns (uint256 c) {
+    // Gas optimization: this is cheaper than asserting 'a' not being zero, but the
+    // benefit is lost if 'b' is also tested.
+    // See: https://github.com/OpenZeppelin/openzeppelin-solidity/pull/522
     if (a == 0) {
       return 0;
     }
-    uint256 c = a * b;
+
+    c = a * b;
     assert(c / a == b);
     return c;
   }
 
+  /**
+  * @dev Integer division of two numbers, truncating the quotient.
+  */
   function div(uint256 a, uint256 b) internal pure returns (uint256) {
     // assert(b > 0); // Solidity automatically throws when dividing by 0
-    uint256 c = a / b;
+    // uint256 c = a / b;
     // assert(a == b * c + a % b); // There is no case in which this doesn't hold
-    return c;
+    return a / b;
   }
 
+  /**
+  * @dev Subtracts two numbers, throws on overflow (i.e. if subtrahend is greater than minuend).
+  */
   function sub(uint256 a, uint256 b) internal pure returns (uint256) {
     assert(b <= a);
     return a - b;
   }
 
-  function add(uint256 a, uint256 b) internal pure returns (uint256) {
-    uint256 c = a + b;
+  /**
+  * @dev Adds two numbers, throws on overflow.
+  */
+  function add(uint256 a, uint256 b) internal pure returns (uint256 c) {
+    c = a + b;
     assert(c >= a);
     return c;
   }

contracts/mocks/AllowanceCrowdsaleImpl.sol

@@ -0,0 +1,21 @@
+pragma solidity ^0.4.23;
+
+import "../token/ERC20/ERC20.sol";
+import "../crowdsale/emission/AllowanceCrowdsale.sol";
+
+
+contract AllowanceCrowdsaleImpl is AllowanceCrowdsale {
+
+  constructor (
+    uint256 _rate,
+    address _wallet,
+    ERC20 _token,
+    address _tokenWallet
+  )
+    public
+    Crowdsale(_rate, _wallet, _token)
+    AllowanceCrowdsale(_tokenWallet)
+  {
+  }
+
+}

contracts/mocks/BasicTokenMock.sol

@@ -1,15 +1,15 @@
-pragma solidity ^0.4.18;
+pragma solidity ^0.4.23;
 
 
-import '../token/BasicToken.sol';
+import "../token/ERC20/BasicToken.sol";
 
 
 // mock class using BasicToken
 contract BasicTokenMock is BasicToken {
 
-  function BasicTokenMock(address initialAccount, uint256 initialBalance) public {
+  constructor(address initialAccount, uint256 initialBalance) public {
     balances[initialAccount] = initialBalance;
-    totalSupply = initialBalance;
+    totalSupply_ = initialBalance;
   }
 
 }

contracts/mocks/BouncerMock.sol

@@ -0,0 +1,22 @@
+pragma solidity ^0.4.23;
+
+import "../access/SignatureBouncer.sol";
+
+
+contract SignatureBouncerMock is SignatureBouncer {
+  function checkValidSignature(address _address, bytes _sig)
+    public
+    view
+    returns (bool)
+  {
+    return isValidSignature(_address, _sig);
+  }
+
+  function onlyWithValidSignature(bytes _sig)
+    onlyValidSignature(_sig)
+    public
+    view
+  {
+
+  }
+}

contracts/mocks/BurnableTokenMock.sol

@@ -1,12 +1,13 @@
-pragma solidity ^0.4.18;
+pragma solidity ^0.4.23;
+
+import "../token/ERC20/BurnableToken.sol";
 
-import '../token/BurnableToken.sol';
 
 contract BurnableTokenMock is BurnableToken {
 
-  function BurnableTokenMock(address initialAccount, uint initialBalance) public {
+  constructor(address initialAccount, uint initialBalance) public {
     balances[initialAccount] = initialBalance;
-    totalSupply = initialBalance;
+    totalSupply_ = initialBalance;
   }
 
 }

contracts/mocks/CappedCrowdsaleImpl.sol

@@ -1,19 +1,19 @@
-pragma solidity ^0.4.18;
+pragma solidity ^0.4.23;
 
-
-import '../crowdsale/CappedCrowdsale.sol';
+import "../token/ERC20/ERC20.sol";
+import "../crowdsale/validation/CappedCrowdsale.sol";
 
 
 contract CappedCrowdsaleImpl is CappedCrowdsale {
 
-  function CappedCrowdsaleImpl (
-    uint256 _startTime,
-    uint256 _endTime,
+  constructor (
     uint256 _rate,
     address _wallet,
+    ERC20 _token,
     uint256 _cap
-  ) public
-    Crowdsale(_startTime, _endTime, _rate, _wallet)
+  )
+    public
+    Crowdsale(_rate, _wallet, _token)
     CappedCrowdsale(_cap)
   {
   }

contracts/mocks/DayLimitMock.sol

@@ -1,23 +0,0 @@
-pragma solidity ^0.4.18;
-import "../../contracts/DayLimit.sol";
-
-contract DayLimitMock is DayLimit {
-  uint256 public totalSpending;
-
-  function DayLimitMock(uint256 _value) public DayLimit(_value) {
-    totalSpending = 0;
-  }
-
-  function attemptSpend(uint256 _value) external limitedDaily(_value) {
-    totalSpending += _value;
-  }
-
-  function setDailyLimit(uint256 _newLimit) external {
-    _setDailyLimit(_newLimit);
-  }
-
-  function resetSpentToday() external {
-    _resetSpentToday();
-  }
-
-}

contracts/mocks/DetailedERC20Mock.sol

@@ -1,8 +1,16 @@
-pragma solidity ^0.4.18;
+pragma solidity ^0.4.23;
+
+import "../token/ERC20/StandardToken.sol";
+import "../token/ERC20/DetailedERC20.sol";
 
-import '../token/StandardToken.sol';
-import '../token/DetailedERC20.sol';
 
 contract DetailedERC20Mock is StandardToken, DetailedERC20 {
-  function DetailedERC20Mock(string _name, string _symbol, uint8 _decimals) DetailedERC20(_name, _symbol, _decimals) public {}
+  constructor(
+    string _name,
+    string _symbol,
+    uint8 _decimals
+  )
+    DetailedERC20(_name, _symbol, _decimals)
+    public
+  {}
 }

contracts/mocks/ECRecoveryMock.sol

@@ -0,0 +1,25 @@
+pragma solidity ^0.4.23;
+
+
+import "../ECRecovery.sol";
+
+
+contract ECRecoveryMock {
+  using ECRecovery for bytes32;
+
+  function recover(bytes32 hash, bytes sig)
+    public
+    pure
+    returns (address)
+  {
+    return hash.recover(sig);
+  }
+
+  function toEthSignedMessageHash(bytes32 hash)
+    public
+    pure
+    returns (bytes32)
+  {
+    return hash.toEthSignedMessageHash();
+  }
+}

contracts/mocks/ERC223TokenMock.sol

@@ -0,0 +1,34 @@
+pragma solidity ^0.4.23;
+
+import "../token/ERC20/BasicToken.sol";
+
+
+contract ERC223ContractInterface {
+  function tokenFallback(address _from, uint256 _value, bytes _data) external;
+}
+
+
+contract ERC223TokenMock is BasicToken {
+
+  constructor(address initialAccount, uint256 initialBalance) public {
+    balances[initialAccount] = initialBalance;
+    totalSupply_ = initialBalance;
+  }
+
+  // ERC223 compatible transfer function (except the name)
+  function transferERC223(address _to, uint256 _value, bytes _data) public
+    returns (bool success)
+  {
+    transfer(_to, _value);
+    bool isContract = false;
+    // solium-disable-next-line security/no-inline-assembly
+    assembly {
+      isContract := not(iszero(extcodesize(_to)))
+    }
+    if (isContract) {
+      ERC223ContractInterface receiver = ERC223ContractInterface(_to);
+      receiver.tokenFallback(msg.sender, _value, _data);
+    }
+    return true;
+  }
+}

contracts/mocks/ERC23TokenMock.sol

@@ -1,33 +0,0 @@
-pragma solidity ^0.4.18;
-
-
-import '../token/BasicToken.sol';
-
-
-contract ERC23ContractInterface {
-  function tokenFallback(address _from, uint256 _value, bytes _data) external;
-}
-
-contract ERC23TokenMock is BasicToken {
-
-  function ERC23TokenMock(address initialAccount, uint256 initialBalance) public {
-    balances[initialAccount] = initialBalance;
-    totalSupply = initialBalance;
-  }
-
-  // ERC23 compatible transfer function (except the name)
-  function transferERC23(address _to, uint256 _value, bytes _data) public
-    returns (bool success)
-  {
-    transfer(_to, _value);
-    bool is_contract = false;
-    assembly {
-      is_contract := not(iszero(extcodesize(_to)))
-    }
-    if(is_contract) {
-      ERC23ContractInterface receiver = ERC23ContractInterface(_to);
-      receiver.tokenFallback(msg.sender, _value, _data);
-    }
-    return true;
-  }
-}

contracts/mocks/ERC721BasicTokenMock.sol

@@ -0,0 +1,18 @@
+pragma solidity ^0.4.23;
+
+import "../token/ERC721/ERC721BasicToken.sol";
+
+
+/**
+ * @title ERC721BasicTokenMock
+ * This mock just provides a public mint and burn functions for testing purposes
+ */
+contract ERC721BasicTokenMock is ERC721BasicToken {
+  function mint(address _to, uint256 _tokenId) public {
+    super._mint(_to, _tokenId);
+  }
+
+  function burn(uint256 _tokenId) public {
+    super._burn(ownerOf(_tokenId), _tokenId);
+  }
+}

contracts/mocks/ERC721ReceiverMock.sol

@@ -0,0 +1,39 @@
+pragma solidity ^0.4.23;
+
+import "../token/ERC721/ERC721Receiver.sol";
+
+
+contract ERC721ReceiverMock is ERC721Receiver {
+  bytes4 retval;
+  bool reverts;
+
+  event Received(
+    address _address,
+    uint256 _tokenId,
+    bytes _data,
+    uint256 _gas
+  );
+
+  constructor(bytes4 _retval, bool _reverts) public {
+    retval = _retval;
+    reverts = _reverts;
+  }
+
+  function onERC721Received(
+    address _address,
+    uint256 _tokenId,
+    bytes _data
+  )
+    public
+    returns(bytes4)
+  {
+    require(!reverts);
+    emit Received(
+      _address,
+      _tokenId,
+      _data,
+      gasleft() // msg.gas was deprecated in solidityv0.4.21
+    );
+    return retval;
+  }
+}

contracts/mocks/ERC721TokenMock.sol

@@ -0,0 +1,27 @@
+pragma solidity ^0.4.23;
+
+import "../token/ERC721/ERC721Token.sol";
+
+
+/**
+ * @title ERC721TokenMock
+ * This mock just provides a public mint and burn functions for testing purposes,
+ * and a public setter for metadata URI
+ */
+contract ERC721TokenMock is ERC721Token {
+  constructor(string name, string symbol) public
+    ERC721Token(name, symbol)
+  { }
+
+  function mint(address _to, uint256 _tokenId) public {
+    super._mint(_to, _tokenId);
+  }
+
+  function burn(uint256 _tokenId) public {
+    super._burn(ownerOf(_tokenId), _tokenId);
+  }
+
+  function setTokenURI(uint256 _tokenId, string _uri) public {
+    super._setTokenURI(_tokenId, _uri);
+  }
+}

contracts/mocks/ERC827TokenMock.sol

@@ -0,0 +1,15 @@
+pragma solidity ^0.4.23;
+
+
+import "../token/ERC827/ERC827Token.sol";
+
+
+// mock class using ERC827 Token
+contract ERC827TokenMock is ERC827Token {
+
+  constructor(address initialAccount, uint256 initialBalance) public {
+    balances[initialAccount] = initialBalance;
+    totalSupply_ = initialBalance;
+  }
+
+}

contracts/mocks/FinalizableCrowdsaleImpl.sol

@@ -1,19 +1,21 @@
-pragma solidity ^0.4.18;
+pragma solidity ^0.4.23;
 
-
-import '../crowdsale/FinalizableCrowdsale.sol';
+import "../token/ERC20/MintableToken.sol";
+import "../crowdsale/distribution/FinalizableCrowdsale.sol";
 
 
 contract FinalizableCrowdsaleImpl is FinalizableCrowdsale {
 
-  function FinalizableCrowdsaleImpl (
-    uint256 _startTime,
-    uint256 _endTime,
+  constructor (
+    uint256 _openingTime,
+    uint256 _closingTime,
     uint256 _rate,
-    address _wallet
-  ) public
-    Crowdsale(_startTime, _endTime, _rate, _wallet)
-    FinalizableCrowdsale()
+    address _wallet,
+    MintableToken _token
+  )
+    public
+    Crowdsale(_rate, _wallet, _token)
+    TimedCrowdsale(_openingTime, _closingTime)
   {
   }
 

contracts/mocks/ForceEther.sol

@@ -1,13 +1,14 @@
-pragma solidity ^0.4.18;
+pragma solidity ^0.4.23;
+
 
 // @title Force Ether into a contract.
 // @notice  even
 // if the contract is not payable.
 // @notice To use, construct the contract with the target as argument.
 // @author Remco Bloemen <remco@neufund.org>
-contract ForceEther  {
+contract ForceEther {
 
-  function ForceEther() public payable { }
+  constructor() public payable { }
 
   function destroyAndSend(address _recipient) public {
     selfdestruct(_recipient);

contracts/mocks/HasNoEtherTest.sol

@@ -1,11 +1,12 @@
-pragma solidity ^0.4.18;
+pragma solidity ^0.4.23;
 
 import "../../contracts/ownership/HasNoEther.sol";
 
+
 contract HasNoEtherTest is HasNoEther {
 
   // Constructor with explicit payable — should still fail
-  function HasNoEtherTest() public payable {
+  constructor() public payable {
   }
 
 }

contracts/mocks/IncreasingPriceCrowdsaleImpl.sol

@@ -0,0 +1,24 @@
+pragma solidity ^0.4.23;
+
+import "../crowdsale/price/IncreasingPriceCrowdsale.sol";
+import "../math/SafeMath.sol";
+
+
+contract IncreasingPriceCrowdsaleImpl is IncreasingPriceCrowdsale {
+
+  constructor (
+    uint256 _openingTime,
+    uint256 _closingTime,
+    address _wallet,
+    ERC20 _token,
+    uint256 _initialRate,
+    uint256 _finalRate
+  )
+    public
+    Crowdsale(_initialRate, _wallet, _token)
+    TimedCrowdsale(_openingTime, _closingTime)
+    IncreasingPriceCrowdsale(_initialRate, _finalRate)
+  {
+  }
+
+}

contracts/mocks/IndividuallyCappedCrowdsaleImpl.sol

@@ -0,0 +1,19 @@
+pragma solidity ^0.4.23;
+
+import "../token/ERC20/ERC20.sol";
+import "../crowdsale/validation/IndividuallyCappedCrowdsale.sol";
+
+
+contract IndividuallyCappedCrowdsaleImpl is IndividuallyCappedCrowdsale {
+
+  constructor (
+    uint256 _rate,
+    address _wallet,
+    ERC20 _token
+  )
+    public
+    Crowdsale(_rate, _wallet, _token)
+  {
+  }
+
+}

contracts/mocks/InsecureTargetBounty.sol

@@ -1,15 +1,15 @@
-pragma solidity ^0.4.18;
-
+pragma solidity ^0.4.23;
 
 import {Bounty, Target} from "../../contracts/Bounty.sol";
 
 
 contract InsecureTargetMock is Target {
-  function checkInvariant() public returns(bool){
+  function checkInvariant() public returns(bool) {
     return false;
   }
 }
 
+
 contract InsecureTargetBounty is Bounty {
   function deployContract() internal returns (address) {
     return new InsecureTargetMock();

contracts/mocks/LimitBalanceMock.sol

@@ -1,7 +1,7 @@
-pragma solidity ^0.4.18;
+pragma solidity ^0.4.23;
 
 
-import '../LimitBalance.sol';
+import "../LimitBalance.sol";
 
 
 // mock class using LimitBalance

contracts/mocks/MathMock.sol

@@ -0,0 +1,26 @@
+pragma solidity ^0.4.23;
+
+
+import "../../contracts/math/Math.sol";
+
+
+contract MathMock {
+  uint64 public result64;
+  uint256 public result256;
+
+  function max64(uint64 a, uint64 b) public {
+    result64 = Math.max64(a, b);
+  }
+
+  function min64(uint64 a, uint64 b) public {
+    result64 = Math.min64(a, b);
+  }
+
+  function max256(uint256 a, uint256 b) public {
+    result256 = Math.max256(a, b);
+  }
+
+  function min256(uint256 a, uint256 b) public {
+    result256 = Math.min256(a, b);
+  }
+}

contracts/mocks/MerkleProofWrapper.sol

@@ -0,0 +1,19 @@
+pragma solidity ^0.4.23;
+
+import { MerkleProof } from "../MerkleProof.sol";
+
+
+contract MerkleProofWrapper {
+
+  function verifyProof(
+    bytes32[] _proof,
+    bytes32 _root,
+    bytes32 _leaf
+  )
+    public
+    pure
+    returns (bool)
+  {
+    return MerkleProof.verifyProof(_proof, _root, _leaf);
+  }
+}

contracts/mocks/MessageHelper.sol

@@ -0,0 +1,50 @@
+pragma solidity ^0.4.23;
+
+
+contract MessageHelper {
+
+  event Show(bytes32 b32, uint256 number, string text);
+  event Buy(bytes32 b32, uint256 number, string text, uint256 value);
+
+  function showMessage(
+    bytes32 message,
+    uint256 number,
+    string text
+  )
+    public
+    returns (bool)
+  {
+    emit Show(message, number, text);
+    return true;
+  }
+
+  function buyMessage(
+    bytes32 message,
+    uint256 number,
+    string text
+  )
+    public
+    payable
+    returns (bool)
+  {
+    emit Buy(
+      message,
+      number,
+      text,
+      msg.value);
+    return true;
+  }
+
+  function fail() public {
+    require(false);
+  }
+
+  function call(address to, bytes data) public returns (bool) {
+    // solium-disable-next-line security/no-low-level-calls
+    if (to.call(data))
+      return true;
+    else
+      return false;
+  }
+
+}

contracts/mocks/MintedCrowdsaleImpl.sol

@@ -0,0 +1,19 @@
+pragma solidity ^0.4.23;
+
+import "../token/ERC20/MintableToken.sol";
+import "../crowdsale/emission/MintedCrowdsale.sol";
+
+
+contract MintedCrowdsaleImpl is MintedCrowdsale {
+
+  constructor (
+    uint256 _rate,
+    address _wallet,
+    MintableToken _token
+  )
+    public
+    Crowdsale(_rate, _wallet, _token)
+  {
+  }
+
+}

contracts/mocks/PausableMock.sol

@@ -1,7 +1,7 @@
-pragma solidity ^0.4.18;
+pragma solidity ^0.4.23;
 
 
-import '../lifecycle/Pausable.sol';
+import "../lifecycle/Pausable.sol";
 
 
 // mock class using Pausable
@@ -9,7 +9,7 @@ contract PausableMock is Pausable {
   bool public drasticMeasureTaken;
   uint256 public count;
 
-  function PausableMock() public {
+  constructor() public {
     drasticMeasureTaken = false;
     count = 0;
   }

contracts/mocks/PausableTokenMock.sol

@@ -1,11 +1,12 @@
-pragma solidity ^0.4.18;
+pragma solidity ^0.4.23;
+
+import "../token/ERC20/PausableToken.sol";
 
-import '../token/PausableToken.sol';
 
 // mock class using PausableToken
 contract PausableTokenMock is PausableToken {
 
-  function PausableTokenMock(address initialAccount, uint initialBalance) public {
+  constructor(address initialAccount, uint initialBalance) public {
     balances[initialAccount] = initialBalance;
   }
 

contracts/mocks/PostDeliveryCrowdsaleImpl.sol

@@ -0,0 +1,22 @@
+pragma solidity ^0.4.23;
+
+import "../token/ERC20/ERC20.sol";
+import "../crowdsale/distribution/PostDeliveryCrowdsale.sol";
+
+
+contract PostDeliveryCrowdsaleImpl is PostDeliveryCrowdsale {
+
+  constructor (
+    uint256 _openingTime,
+    uint256 _closingTime,
+    uint256 _rate,
+    address _wallet,
+    ERC20 _token
+  )
+    public
+    TimedCrowdsale(_openingTime, _closingTime)
+    Crowdsale(_rate, _wallet, _token)
+  {
+  }
+
+}

contracts/mocks/PullPaymentMock.sol

@@ -1,13 +1,13 @@
-pragma solidity ^0.4.18;
+pragma solidity ^0.4.23;
 
 
-import '../payment/PullPayment.sol';
+import "../payment/PullPayment.sol";
 
 
 // mock class using PullPayment
 contract PullPaymentMock is PullPayment {
 
-  function PullPaymentMock() public payable { }
+  constructor() public payable { }
 
   // test helper function to call asyncSend
   function callSend(address dest, uint256 amount) public {

contracts/mocks/RBACMock.sol

@@ -1,69 +1,69 @@
-pragma solidity ^0.4.8;
+pragma solidity ^0.4.23;
 
-import '../ownership/rbac/RBAC.sol';
+import "../examples/RBACWithAdmin.sol";
 
 
-contract RBACMock is RBAC {
+contract RBACMock is RBACWithAdmin {
 
-    string constant ROLE_ADVISOR = "advisor";
+  string constant ROLE_ADVISOR = "advisor";
 
-    modifier onlyAdminOrAdvisor()
-    {
-        require(
-            hasRole(msg.sender, ROLE_ADMIN) ||
-            hasRole(msg.sender, ROLE_ADVISOR)
-        );
-        _;
+  modifier onlyAdminOrAdvisor()
+  {
+    require(
+      hasRole(msg.sender, ROLE_ADMIN) ||
+      hasRole(msg.sender, ROLE_ADVISOR)
+    );
+    _;
+  }
+
+  constructor(address[] _advisors)
+    public
+  {
+    addRole(msg.sender, ROLE_ADVISOR);
+
+    for (uint256 i = 0; i < _advisors.length; i++) {
+      addRole(_advisors[i], ROLE_ADVISOR);
     }
+  }
 
-    function RBACMock(address[] _advisors)
-        public
-    {
-        addRole(msg.sender, ROLE_ADVISOR);
+  function onlyAdminsCanDoThis()
+    onlyAdmin
+    view
+    external
+  {
+  }
 
-        for (uint256 i = 0; i < _advisors.length; i++) {
-            addRole(_advisors[i], ROLE_ADVISOR);
-        }
-    }
+  function onlyAdvisorsCanDoThis()
+    onlyRole(ROLE_ADVISOR)
+    view
+    external
+  {
+  }
 
-    function onlyAdminsCanDoThis()
-        onlyAdmin
-        view
-        external
-    {
-    }
+  function eitherAdminOrAdvisorCanDoThis()
+    onlyAdminOrAdvisor
+    view
+    external
+  {
+  }
 
-    function onlyAdvisorsCanDoThis()
-        onlyRole(ROLE_ADVISOR)
-        view
-        external
-    {
-    }
+  function nobodyCanDoThis()
+    onlyRole("unknown")
+    view
+    external
+  {
+  }
 
-    function eitherAdminOrAdvisorCanDoThis()
-        onlyAdminOrAdvisor
-        view
-        external
-    {
-    }
+  // admins can remove advisor's role
+  function removeAdvisor(address _addr)
+    onlyAdmin
+    public
+  {
+    // revert if the user isn't an advisor
+    //  (perhaps you want to soft-fail here instead?)
+    checkRole(_addr, ROLE_ADVISOR);
 
-    function nobodyCanDoThis()
-        onlyRole("unknown")
-        view
-        external
-    {
-    }
-
-    // admins can remove advisor's role
-    function removeAdvisor(address _addr)
-        onlyAdmin
-        public
-    {
-        // revert if the user isn't an advisor
-        //  (perhaps you want to soft-fail here instead?)
-        checkRole(_addr, ROLE_ADVISOR);
-
-        // remove the advisor's role
-        removeRole(_addr, ROLE_ADVISOR);
-    }
+    // remove the advisor's role
+    removeRole(_addr, ROLE_ADVISOR);
+  }
 }

contracts/mocks/ReentrancyAttack.sol

@@ -1,8 +1,10 @@
-pragma solidity ^0.4.18;
+pragma solidity ^0.4.23;
+
 
 contract ReentrancyAttack {
 
   function callSender(bytes4 data) public {
+    // solium-disable-next-line security/no-low-level-calls
     require(msg.sender.call(data));
   }
 

contracts/mocks/ReentrancyMock.sol

@@ -1,22 +1,23 @@
-pragma solidity ^0.4.18;
+pragma solidity ^0.4.23;
+
+import "../ReentrancyGuard.sol";
+import "./ReentrancyAttack.sol";
 
-import '../ReentrancyGuard.sol';
-import './ReentrancyAttack.sol';
 
 contract ReentrancyMock is ReentrancyGuard {
 
   uint256 public counter;
 
-  function ReentrancyMock() public {
+  constructor() public {
     counter = 0;
   }
 
-  function count() private {
-    counter += 1;
+  function callback() external nonReentrant {
+    count();
   }
 
   function countLocalRecursive(uint256 n) public nonReentrant {
-    if(n > 0) {
+    if (n > 0) {
       count();
       countLocalRecursive(n - 1);
     }
@@ -24,9 +25,10 @@ contract ReentrancyMock is ReentrancyGuard {
 
   function countThisRecursive(uint256 n) public nonReentrant {
     bytes4 func = bytes4(keccak256("countThisRecursive(uint256)"));
-    if(n > 0) {
+    if (n > 0) {
       count();
-      bool result = this.call(func, n - 1);
+      // solium-disable-next-line security/no-low-level-calls
+      bool result = address(this).call(func, n - 1);
       require(result == true);
     }
   }
@@ -37,8 +39,8 @@ contract ReentrancyMock is ReentrancyGuard {
     attacker.callSender(func);
   }
 
-  function callback() external nonReentrant {
-    count();
+  function count() private {
+    counter += 1;
   }
 
 }

contracts/mocks/RefundableCrowdsaleImpl.sol

@@ -1,19 +1,22 @@
-pragma solidity ^0.4.18;
+pragma solidity ^0.4.23;
 
-
-import '../crowdsale/RefundableCrowdsale.sol';
+import "../token/ERC20/MintableToken.sol";
+import "../crowdsale/distribution/RefundableCrowdsale.sol";
 
 
 contract RefundableCrowdsaleImpl is RefundableCrowdsale {
 
-  function RefundableCrowdsaleImpl (
-    uint256 _startTime,
-    uint256 _endTime,
+  constructor (
+    uint256 _openingTime,
+    uint256 _closingTime,
     uint256 _rate,
     address _wallet,
+    MintableToken _token,
     uint256 _goal
-  ) public
-    Crowdsale(_startTime, _endTime, _rate, _wallet)
+  )
+    public
+    Crowdsale(_rate, _wallet, _token)
+    TimedCrowdsale(_openingTime, _closingTime)
     RefundableCrowdsale(_goal)
   {
   }

contracts/mocks/SafeERC20Helper.sol

@@ -1,9 +1,14 @@
-pragma solidity ^0.4.18;
+pragma solidity ^0.4.23;
+
+import "../token/ERC20/ERC20.sol";
+import "../token/ERC20/SafeERC20.sol";
 
-import '../token/ERC20.sol';
-import '../token/SafeERC20.sol';
 
 contract ERC20FailingMock is ERC20 {
+  function totalSupply() public view returns (uint256) {
+    return 0;
+  }
+
   function transfer(address, uint256) public returns (bool) {
     return false;
   }
@@ -16,16 +21,21 @@ contract ERC20FailingMock is ERC20 {
     return false;
   }
 
-  function balanceOf(address) public constant returns (uint256) {
+  function balanceOf(address) public view returns (uint256) {
     return 0;
   }
 
-  function allowance(address, address) public constant returns (uint256) {
+  function allowance(address, address) public view returns (uint256) {
     return 0;
   }
 }
 
+
 contract ERC20SucceedingMock is ERC20 {
+  function totalSupply() public view returns (uint256) {
+    return 0;
+  }
+
   function transfer(address, uint256) public returns (bool) {
     return true;
   }
@@ -38,22 +48,23 @@ contract ERC20SucceedingMock is ERC20 {
     return true;
   }
 
-  function balanceOf(address) public constant returns (uint256) {
+  function balanceOf(address) public view returns (uint256) {
     return 0;
   }
 
-  function allowance(address, address) public constant returns (uint256) {
+  function allowance(address, address) public view returns (uint256) {
     return 0;
   }
 }
 
+
 contract SafeERC20Helper {
   using SafeERC20 for ERC20;
 
   ERC20 failing;
   ERC20 succeeding;
 
-  function SafeERC20Helper() public {
+  constructor() public {
     failing = new ERC20FailingMock();
     succeeding = new ERC20SucceedingMock();
   }

contracts/mocks/SafeMathMock.sol

@@ -1,21 +1,24 @@
-pragma solidity ^0.4.18;
+pragma solidity ^0.4.23;
 
 
-import '../math/SafeMath.sol';
+import "../math/SafeMath.sol";
 
 
 contract SafeMathMock {
-  uint256 public result;
 
-  function multiply(uint256 a, uint256 b) public {
-    result = SafeMath.mul(a, b);
+  function mul(uint256 a, uint256 b) public pure returns (uint256) {
+    return SafeMath.mul(a, b);
   }
 
-  function subtract(uint256 a, uint256 b) public {
-    result = SafeMath.sub(a, b);
+  function div(uint256 a, uint256 b) public pure returns (uint256) {
+    return SafeMath.div(a, b);
   }
 
-  function add(uint256 a, uint256 b) public {
-    result = SafeMath.add(a, b);
+  function sub(uint256 a, uint256 b) public pure returns (uint256) {
+    return SafeMath.sub(a, b);
+  }
+
+  function add(uint256 a, uint256 b) public pure returns (uint256) {
+    return SafeMath.add(a, b);
   }
 }

contracts/mocks/SecureTargetBounty.sol

@@ -1,5 +1,4 @@
-pragma solidity ^0.4.18;
-
+pragma solidity ^0.4.23;
 
 import {Bounty, Target} from "../../contracts/Bounty.sol";
 
@@ -10,6 +9,7 @@ contract SecureTargetMock is Target {
   }
 }
 
+
 contract SecureTargetBounty is Bounty {
   function deployContract() internal returns (address) {
     return new SecureTargetMock();

contracts/mocks/StandardBurnableTokenMock.sol

@@ -0,0 +1,13 @@
+pragma solidity ^0.4.23;
+
+import "../token/ERC20/StandardBurnableToken.sol";
+
+
+contract StandardBurnableTokenMock is StandardBurnableToken {
+
+  constructor(address initialAccount, uint initialBalance) public {
+    balances[initialAccount] = initialBalance;
+    totalSupply_ = initialBalance;
+  }
+
+}

contracts/mocks/StandardTokenMock.sol

@@ -1,15 +1,14 @@
-pragma solidity ^0.4.18;
+pragma solidity ^0.4.23;
 
-
-import '../token/StandardToken.sol';
+import "../token/ERC20/StandardToken.sol";
 
 
 // mock class using StandardToken
 contract StandardTokenMock is StandardToken {
 
-  function StandardTokenMock(address initialAccount, uint256 initialBalance) public {
+  constructor(address initialAccount, uint256 initialBalance) public {
     balances[initialAccount] = initialBalance;
-    totalSupply = initialBalance;
+    totalSupply_ = initialBalance;
   }
 
 }

contracts/mocks/TimedCrowdsaleImpl.sol

@@ -0,0 +1,22 @@
+pragma solidity ^0.4.23;
+
+import "../token/ERC20/ERC20.sol";
+import "../crowdsale/validation/TimedCrowdsale.sol";
+
+
+contract TimedCrowdsaleImpl is TimedCrowdsale {
+
+  constructor (
+    uint256 _openingTime,
+    uint256 _closingTime,
+    uint256 _rate,
+    address _wallet,
+    ERC20 _token
+  )
+    public
+    Crowdsale(_rate, _wallet, _token)
+    TimedCrowdsale(_openingTime, _closingTime)
+  {
+  }
+
+}

contracts/mocks/WhitelistMock.sol

@@ -0,0 +1,14 @@
+pragma solidity ^0.4.23;
+
+import "../ownership/Whitelist.sol";
+
+
+contract WhitelistMock is Whitelist {
+
+  function onlyWhitelistedCanDoThis()
+    onlyWhitelisted
+    view
+    external
+  {
+  }
+}

contracts/mocks/WhitelistedCrowdsaleImpl.sol

@@ -0,0 +1,19 @@
+pragma solidity ^0.4.23;
+
+import "../token/ERC20/ERC20.sol";
+import "../crowdsale/validation/WhitelistedCrowdsale.sol";
+
+
+contract WhitelistedCrowdsaleImpl is WhitelistedCrowdsale {
+
+  constructor (
+    uint256 _rate,
+    address _wallet,
+    ERC20 _token
+  )
+    public
+    Crowdsale(_rate, _wallet, _token)
+  {
+  }
+
+}

contracts/ownership/CanReclaimToken.sol

@@ -1,8 +1,9 @@
-pragma solidity ^0.4.18;
+pragma solidity ^0.4.23;
 
 import "./Ownable.sol";
-import "../token/ERC20Basic.sol";
-import "../token/SafeERC20.sol";
+import "../token/ERC20/ERC20Basic.sol";
+import "../token/ERC20/SafeERC20.sol";
+
 
 /**
  * @title Contracts that should be able to recover tokens

contracts/ownership/Claimable.sol

@@ -1,7 +1,7 @@
-pragma solidity ^0.4.18;
+pragma solidity ^0.4.23;
 
 
-import './Ownable.sol';
+import "./Ownable.sol";
 
 
 /**
@@ -32,7 +32,7 @@ contract Claimable is Ownable {
    * @dev Allows the pendingOwner address to finalize the transfer.
    */
   function claimOwnership() onlyPendingOwner public {
-    OwnershipTransferred(owner, pendingOwner);
+    emit OwnershipTransferred(owner, pendingOwner);
     owner = pendingOwner;
     pendingOwner = address(0);
   }

contracts/ownership/Contactable.sol

@@ -1,21 +1,22 @@
-pragma solidity ^0.4.18;
+pragma solidity ^0.4.23;
+
+import "./Ownable.sol";
 
-import './Ownable.sol';
 
 /**
  * @title Contactable token
  * @dev Basic version of a contactable contract, allowing the owner to provide a string with their
  * contact information.
  */
-contract Contactable is Ownable{
+contract Contactable is Ownable {
 
-    string public contactInformation;
+  string public contactInformation;
 
-    /**
-     * @dev Allows the owner to set a string with their contact information.
-     * @param info The contact information to attach to the contract.
-     */
-    function setContactInformation(string info) onlyOwner public {
-         contactInformation = info;
-     }
+  /**
+    * @dev Allows the owner to set a string with their contact information.
+    * @param info The contact information to attach to the contract.
+    */
+  function setContactInformation(string info) onlyOwner public {
+    contactInformation = info;
+  }
 }

contracts/ownership/DelayedClaimable.sol

@@ -1,7 +1,6 @@
-pragma solidity ^0.4.18;
+pragma solidity ^0.4.23;
 
-
-import './Claimable.sol';
+import "./Claimable.sol";
 
 
 /**
@@ -26,14 +25,13 @@ contract DelayedClaimable is Claimable {
     start = _start;
   }
 
-
   /**
    * @dev Allows the pendingOwner address to finalize the transfer, as long as it is called within
    * the specified start and end time.
    */
   function claimOwnership() onlyPendingOwner public {
     require((block.number <= end) && (block.number >= start));
-    OwnershipTransferred(owner, pendingOwner);
+    emit OwnershipTransferred(owner, pendingOwner);
     owner = pendingOwner;
     pendingOwner = address(0);
     end = 0;

contracts/ownership/HasNoContracts.sol

@@ -1,7 +1,8 @@
-pragma solidity ^0.4.18;
+pragma solidity ^0.4.23;
 
 import "./Ownable.sol";
 
+
 /**
  * @title Contracts that should not own Contracts
  * @author Remco Bloemen <remco@2π.com>

contracts/ownership/HasNoEther.sol

@@ -1,17 +1,18 @@
-pragma solidity ^0.4.18;
+pragma solidity ^0.4.23;
 
 import "./Ownable.sol";
 
+
 /**
  * @title Contracts that should not own Ether
  * @author Remco Bloemen <remco@2π.com>
  * @dev This tries to block incoming ether to prevent accidental loss of Ether. Should Ether end up
  * in the contract, it will allow the owner to reclaim this ether.
- * @notice Ether can still be send to this contract by:
+ * @notice Ether can still be sent to this contract by:
  * calling functions labeled `payable`
  * `selfdestruct(contract_address)`
  * mining directly to the contract address
-*/
+ */
 contract HasNoEther is Ownable {
 
   /**
@@ -21,7 +22,7 @@ contract HasNoEther is Ownable {
   * constructor. By doing it this way we prevent a payable constructor from working. Alternatively
   * we could use assembly to access msg.value.
   */
-  function HasNoEther() public payable {
+  constructor() public payable {
     require(msg.value == 0);
   }
 
@@ -35,6 +36,6 @@ contract HasNoEther is Ownable {
    * @dev Transfer all Ether held by the contract to the owner.
    */
   function reclaimEther() external onlyOwner {
-    assert(owner.send(this.balance));
+    owner.transfer(address(this).balance);
   }
 }

contracts/ownership/HasNoTokens.sol

@@ -1,18 +1,19 @@
-pragma solidity ^0.4.18;
+pragma solidity ^0.4.23;
 
 import "./CanReclaimToken.sol";
 
+
 /**
  * @title Contracts that should not own Tokens
  * @author Remco Bloemen <remco@2π.com>
- * @dev This blocks incoming ERC23 tokens to prevent accidental loss of tokens.
+ * @dev This blocks incoming ERC223 tokens to prevent accidental loss of tokens.
  * Should tokens (any ERC20Basic compatible) end up in the contract, it allows the
  * owner to reclaim the tokens.
  */
 contract HasNoTokens is CanReclaimToken {
 
  /**
-  * @dev Reject all ERC23 compatible tokens
+  * @dev Reject all ERC223 compatible tokens
   * @param from_ address The address that is transferring the tokens
   * @param value_ uint256 the amount of the specified token
   * @param data_ Bytes The data passed from the caller.

contracts/ownership/Heritable.sol

@@ -0,0 +1,126 @@
+pragma solidity ^0.4.23;
+
+
+import "./Ownable.sol";
+
+
+/**
+ * @title Heritable
+ * @dev The Heritable contract provides ownership transfer capabilities, in the
+ * case that the current owner stops "heartbeating". Only the heir can pronounce the
+ * owner's death.
+ */
+contract Heritable is Ownable {
+  address private heir_;
+
+  // Time window the owner has to notify they are alive.
+  uint256 private heartbeatTimeout_;
+
+  // Timestamp of the owner's death, as pronounced by the heir.
+  uint256 private timeOfDeath_;
+
+  event HeirChanged(address indexed owner, address indexed newHeir);
+  event OwnerHeartbeated(address indexed owner);
+  event OwnerProclaimedDead(
+    address indexed owner,
+    address indexed heir,
+    uint256 timeOfDeath
+  );
+  event HeirOwnershipClaimed(
+    address indexed previousOwner,
+    address indexed newOwner
+  );
+
+
+  /**
+   * @dev Throw an exception if called by any account other than the heir's.
+   */
+  modifier onlyHeir() {
+    require(msg.sender == heir_);
+    _;
+  }
+
+
+  /**
+   * @notice Create a new Heritable Contract with heir address 0x0.
+   * @param _heartbeatTimeout time available for the owner to notify they are alive,
+   * before the heir can take ownership.
+   */
+  constructor(uint256 _heartbeatTimeout) public {
+    setHeartbeatTimeout(_heartbeatTimeout);
+  }
+
+  function setHeir(address newHeir) public onlyOwner {
+    require(newHeir != owner);
+    heartbeat();
+    emit HeirChanged(owner, newHeir);
+    heir_ = newHeir;
+  }
+
+  /**
+   * @dev Use these getter functions to access the internal variables in
+   * an inherited contract.
+   */
+  function heir() public view returns(address) {
+    return heir_;
+  }
+
+  function heartbeatTimeout() public view returns(uint256) {
+    return heartbeatTimeout_;
+  }
+
+  function timeOfDeath() public view returns(uint256) {
+    return timeOfDeath_;
+  }
+
+  /**
+   * @dev set heir = 0x0
+   */
+  function removeHeir() public onlyOwner {
+    heartbeat();
+    heir_ = 0;
+  }
+
+  /**
+   * @dev Heir can pronounce the owners death. To claim the ownership, they will
+   * have to wait for `heartbeatTimeout` seconds.
+   */
+  function proclaimDeath() public onlyHeir {
+    require(ownerLives());
+    emit OwnerProclaimedDead(owner, heir_, timeOfDeath_);
+    // solium-disable-next-line security/no-block-members
+    timeOfDeath_ = block.timestamp;
+  }
+
+  /**
+   * @dev Owner can send a heartbeat if they were mistakenly pronounced dead.
+   */
+  function heartbeat() public onlyOwner {
+    emit OwnerHeartbeated(owner);
+    timeOfDeath_ = 0;
+  }
+
+  /**
+   * @dev Allows heir to transfer ownership only if heartbeat has timed out.
+   */
+  function claimHeirOwnership() public onlyHeir {
+    require(!ownerLives());
+    // solium-disable-next-line security/no-block-members
+    require(block.timestamp >= timeOfDeath_ + heartbeatTimeout_);
+    emit OwnershipTransferred(owner, heir_);
+    emit HeirOwnershipClaimed(owner, heir_);
+    owner = heir_;
+    timeOfDeath_ = 0;
+  }
+
+  function setHeartbeatTimeout(uint256 newHeartbeatTimeout)
+    internal onlyOwner
+  {
+    require(ownerLives());
+    heartbeatTimeout_ = newHeartbeatTimeout;
+  }
+
+  function ownerLives() internal view returns (bool) {
+    return timeOfDeath_ == 0;
+  }
+}

contracts/ownership/NoOwner.sol

@@ -1,9 +1,10 @@
-pragma solidity ^0.4.18;
+pragma solidity ^0.4.23;
 
 import "./HasNoEther.sol";
 import "./HasNoTokens.sol";
 import "./HasNoContracts.sol";
 
+
 /**
  * @title Base contract for contracts that should not own things.
  * @author Remco Bloemen <remco@2π.com>

contracts/ownership/Ownable.sol

@@ -1,4 +1,4 @@
-pragma solidity ^0.4.18;
+pragma solidity ^0.4.23;
 
 
 /**
@@ -10,18 +10,21 @@ contract Ownable {
   address public owner;
 
 
-  event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
+  event OwnershipRenounced(address indexed previousOwner);
+  event OwnershipTransferred(
+    address indexed previousOwner,
+    address indexed newOwner
+  );
 
 
   /**
    * @dev The Ownable constructor sets the original `owner` of the contract to the sender
    * account.
    */
-  function Ownable() public {
+  constructor() public {
     owner = msg.sender;
   }
 
-
   /**
    * @dev Throws if called by any account other than the owner.
    */
@@ -30,15 +33,29 @@ contract Ownable {
     _;
   }
 
+  /**
+   * @dev Allows the current owner to relinquish control of the contract.
+   */
+  function renounceOwnership() public onlyOwner {
+    emit OwnershipRenounced(owner);
+    owner = address(0);
+  }
 
   /**
    * @dev Allows the current owner to transfer control of the contract to a newOwner.
-   * @param newOwner The address to transfer ownership to.
+   * @param _newOwner The address to transfer ownership to.
    */
-  function transferOwnership(address newOwner) public onlyOwner {
-    require(newOwner != address(0));
-    OwnershipTransferred(owner, newOwner);
-    owner = newOwner;
+  function transferOwnership(address _newOwner) public onlyOwner {
+    _transferOwnership(_newOwner);
   }
 
+  /**
+   * @dev Transfers control of the contract to a newOwner.
+   * @param _newOwner The address to transfer ownership to.
+   */
+  function _transferOwnership(address _newOwner) internal {
+    require(_newOwner != address(0));
+    emit OwnershipTransferred(owner, _newOwner);
+    owner = _newOwner;
+  }
 }

contracts/ownership/Superuser.sol

@@ -0,0 +1,62 @@
+pragma solidity ^0.4.23;
+
+
+import "./Ownable.sol";
+import "./rbac/RBAC.sol";
+
+
+/**
+ * @title Superuser
+ * @dev The Superuser contract defines a single superuser who can transfer the ownership 
+ * @dev of a contract to a new address, even if he is not the owner. 
+ * @dev A superuser can transfer his role to a new address. 
+ */
+contract Superuser is Ownable, RBAC {
+  string public constant ROLE_SUPERUSER = "superuser";
+
+  constructor () public {
+    addRole(msg.sender, ROLE_SUPERUSER);
+  }
+
+  /**
+   * @dev Throws if called by any account that's not a superuser.
+   */
+  modifier onlySuperuser() {
+    checkRole(msg.sender, ROLE_SUPERUSER);
+    _;
+  }
+
+  modifier onlyOwnerOrSuperuser() {
+    require(msg.sender == owner || isSuperuser(msg.sender));
+    _;
+  }
+
+  /**
+   * @dev getter to determine if address has superuser role
+   */
+  function isSuperuser(address _addr)
+    public
+    view
+    returns (bool)
+  {
+    return hasRole(_addr, ROLE_SUPERUSER);
+  }
+
+  /**
+   * @dev Allows the current superuser to transfer his role to a newSuperuser.
+   * @param _newSuperuser The address to transfer ownership to.
+   */
+  function transferSuperuser(address _newSuperuser) public onlySuperuser {
+    require(_newSuperuser != address(0));
+    removeRole(msg.sender, ROLE_SUPERUSER);
+    addRole(_newSuperuser, ROLE_SUPERUSER);
+  }
+
+  /**
+   * @dev Allows the current superuser or owner to transfer control of the contract to a newOwner.
+   * @param _newOwner The address to transfer ownership to.
+   */
+  function transferOwnership(address _newOwner) public onlyOwnerOrSuperuser {
+    _transferOwnership(_newOwner);
+  }
+}

contracts/ownership/Whitelist.sol

@@ -0,0 +1,95 @@
+pragma solidity ^0.4.23;
+
+
+import "./Ownable.sol";
+import "./rbac/RBAC.sol";
+
+
+/**
+ * @title Whitelist
+ * @dev The Whitelist contract has a whitelist of addresses, and provides basic authorization control functions.
+ * @dev This simplifies the implementation of "user permissions".
+ */
+contract Whitelist is Ownable, RBAC {
+  event WhitelistedAddressAdded(address addr);
+  event WhitelistedAddressRemoved(address addr);
+
+  string public constant ROLE_WHITELISTED = "whitelist";
+
+  /**
+   * @dev Throws if called by any account that's not whitelisted.
+   */
+  modifier onlyWhitelisted() {
+    checkRole(msg.sender, ROLE_WHITELISTED);
+    _;
+  }
+
+  /**
+   * @dev add an address to the whitelist
+   * @param addr address
+   * @return true if the address was added to the whitelist, false if the address was already in the whitelist
+   */
+  function addAddressToWhitelist(address addr)
+    onlyOwner
+    public
+  {
+    addRole(addr, ROLE_WHITELISTED);
+    emit WhitelistedAddressAdded(addr);
+  }
+
+  /**
+   * @dev getter to determine if address is in whitelist
+   */
+  function whitelist(address addr)
+    public
+    view
+    returns (bool)
+  {
+    return hasRole(addr, ROLE_WHITELISTED);
+  }
+
+  /**
+   * @dev add addresses to the whitelist
+   * @param addrs addresses
+   * @return true if at least one address was added to the whitelist,
+   * false if all addresses were already in the whitelist
+   */
+  function addAddressesToWhitelist(address[] addrs)
+    onlyOwner
+    public
+  {
+    for (uint256 i = 0; i < addrs.length; i++) {
+      addAddressToWhitelist(addrs[i]);
+    }
+  }
+
+  /**
+   * @dev remove an address from the whitelist
+   * @param addr address
+   * @return true if the address was removed from the whitelist,
+   * false if the address wasn't in the whitelist in the first place
+   */
+  function removeAddressFromWhitelist(address addr)
+    onlyOwner
+    public
+  {
+    removeRole(addr, ROLE_WHITELISTED);
+    emit WhitelistedAddressRemoved(addr);
+  }
+
+  /**
+   * @dev remove addresses from the whitelist
+   * @param addrs addresses
+   * @return true if at least one address was removed from the whitelist,
+   * false if all addresses weren't in the whitelist in the first place
+   */
+  function removeAddressesFromWhitelist(address[] addrs)
+    onlyOwner
+    public
+  {
+    for (uint256 i = 0; i < addrs.length; i++) {
+      removeAddressFromWhitelist(addrs[i]);
+    }
+  }
+
+}

contracts/ownership/rbac/RBAC.sol

@@ -1,157 +1,108 @@
-pragma solidity ^0.4.18;
+pragma solidity ^0.4.23;
 
-import './Roles.sol';
+import "./Roles.sol";
 
 
 /**
  * @title RBAC (Role-Based Access Control)
  * @author Matt Condon (@Shrugs)
  * @dev Stores and provides setters and getters for roles and addresses.
- *      Supports unlimited numbers of roles and addresses.
- *      See //contracts/examples/RBACExample.sol for an example of usage.
+ * @dev Supports unlimited numbers of roles and addresses.
+ * @dev See //contracts/mocks/RBACMock.sol for an example of usage.
  * This RBAC method uses strings to key roles. It may be beneficial
  *  for you to write your own implementation of this interface using Enums or similar.
  * It's also recommended that you define constants in the contract, like ROLE_ADMIN below,
  *  to avoid typos.
  */
 contract RBAC {
-    using Roles for Roles.Role;
+  using Roles for Roles.Role;
 
-    mapping (string => Roles.Role) private roles;
+  mapping (string => Roles.Role) private roles;
 
-    event RoleAdded(address addr, string roleName);
-    event RoleRemoved(address addr, string roleName);
+  event RoleAdded(address addr, string roleName);
+  event RoleRemoved(address addr, string roleName);
 
-    /**
-     * A constant role name for indicating admins.
-     */
-    string public constant ROLE_ADMIN = "admin";
+  /**
+   * @dev reverts if addr does not have role
+   * @param addr address
+   * @param roleName the name of the role
+   * // reverts
+   */
+  function checkRole(address addr, string roleName)
+    view
+    public
+  {
+    roles[roleName].check(addr);
+  }
 
-    /**
-     * @dev constructor. Sets msg.sender as admin by default
-     */
-    function RBAC()
-        public
-    {
-        addRole(msg.sender, ROLE_ADMIN);
-    }
+  /**
+   * @dev determine if addr has role
+   * @param addr address
+   * @param roleName the name of the role
+   * @return bool
+   */
+  function hasRole(address addr, string roleName)
+    view
+    public
+    returns (bool)
+  {
+    return roles[roleName].has(addr);
+  }
 
-    /**
-     * @dev add a role to an address
-     * @param addr address
-     * @param roleName the name of the role
-     */
-    function addRole(address addr, string roleName)
-        internal
-    {
-        roles[roleName].add(addr);
-        RoleAdded(addr, roleName);
-    }
+  /**
+   * @dev add a role to an address
+   * @param addr address
+   * @param roleName the name of the role
+   */
+  function addRole(address addr, string roleName)
+    internal
+  {
+    roles[roleName].add(addr);
+    emit RoleAdded(addr, roleName);
+  }
 
-    /**
-     * @dev remove a role from an address
-     * @param addr address
-     * @param roleName the name of the role
-     */
-    function removeRole(address addr, string roleName)
-        internal
-    {
-        roles[roleName].remove(addr);
-        RoleRemoved(addr, roleName);
-    }
+  /**
+   * @dev remove a role from an address
+   * @param addr address
+   * @param roleName the name of the role
+   */
+  function removeRole(address addr, string roleName)
+    internal
+  {
+    roles[roleName].remove(addr);
+    emit RoleRemoved(addr, roleName);
+  }
 
-    /**
-     * @dev reverts if addr does not have role
-     * @param addr address
-     * @param roleName the name of the role
-     * // reverts
-     */
-    function checkRole(address addr, string roleName)
-        view
-        public
-    {
-        roles[roleName].check(addr);
-    }
+  /**
+   * @dev modifier to scope access to a single role (uses msg.sender as addr)
+   * @param roleName the name of the role
+   * // reverts
+   */
+  modifier onlyRole(string roleName)
+  {
+    checkRole(msg.sender, roleName);
+    _;
+  }
 
-    /**
-     * @dev determine if addr has role
-     * @param addr address
-     * @param roleName the name of the role
-     * @return bool
-     */
-    function hasRole(address addr, string roleName)
-        view
-        public
-        returns (bool)
-    {
-        return roles[roleName].has(addr);
-    }
+  /**
+   * @dev modifier to scope access to a set of roles (uses msg.sender as addr)
+   * @param roleNames the names of the roles to scope access to
+   * // reverts
+   *
+   * @TODO - when solidity supports dynamic arrays as arguments to modifiers, provide this
+   *  see: https://github.com/ethereum/solidity/issues/2467
+   */
+  // modifier onlyRoles(string[] roleNames) {
+  //     bool hasAnyRole = false;
+  //     for (uint8 i = 0; i < roleNames.length; i++) {
+  //         if (hasRole(msg.sender, roleNames[i])) {
+  //             hasAnyRole = true;
+  //             break;
+  //         }
+  //     }
 
-    /**
-     * @dev add a role to an address
-     * @param addr address
-     * @param roleName the name of the role
-     */
-    function adminAddRole(address addr, string roleName)
-        onlyAdmin
-        public
-    {
-        addRole(addr, roleName);
-    }
+  //     require(hasAnyRole);
 
-    /**
-     * @dev remove a role from an address
-     * @param addr address
-     * @param roleName the name of the role
-     */
-    function adminRemoveRole(address addr, string roleName)
-        onlyAdmin
-        public
-    {
-        removeRole(addr, roleName);
-    }
-
-
-    /**
-     * @dev modifier to scope access to a single role (uses msg.sender as addr)
-     * @param roleName the name of the role
-     * // reverts
-     */
-    modifier onlyRole(string roleName)
-    {
-        checkRole(msg.sender, roleName);
-        _;
-    }
-
-    /**
-     * @dev modifier to scope access to admins
-     * // reverts
-     */
-    modifier onlyAdmin()
-    {
-        checkRole(msg.sender, ROLE_ADMIN);
-        _;
-    }
-
-    /**
-     * @dev modifier to scope access to a set of roles (uses msg.sender as addr)
-     * @param roleNames the names of the roles to scope access to
-     * // reverts
-     *
-     * @TODO - when solidity supports dynamic arrays as arguments to modifiers, provide this
-     *  see: https://github.com/ethereum/solidity/issues/2467
-     */
-    // modifier onlyRoles(string[] roleNames) {
-    //     bool hasAnyRole = false;
-    //     for (uint8 i = 0; i < roleNames.length; i++) {
-    //         if (hasRole(msg.sender, roleNames[i])) {
-    //             hasAnyRole = true;
-    //             break;
-    //         }
-    //     }
-
-    //     require(hasAnyRole);
-
-    //     _;
-    // }
+  //     _;
+  // }
 }

contracts/ownership/rbac/Roles.sol

@@ -1,4 +1,4 @@
-pragma solidity ^0.4.18;
+pragma solidity ^0.4.23;
 
 
 /**
@@ -8,48 +8,48 @@ pragma solidity ^0.4.18;
  *      See RBAC.sol for example usage.
  */
 library Roles {
-    struct Role {
-        mapping (address => bool) bearer;
-    }
+  struct Role {
+    mapping (address => bool) bearer;
+  }
 
-    /**
-     * @dev give an address access to this role
-     */
-    function add(Role storage role, address addr)
-        internal
-    {
-        role.bearer[addr] = true;
-    }
+  /**
+   * @dev give an address access to this role
+   */
+  function add(Role storage role, address addr)
+    internal
+  {
+    role.bearer[addr] = true;
+  }
 
-    /**
-     * @dev remove an address' access to this role
-     */
-    function remove(Role storage role, address addr)
-        internal
-    {
-        role.bearer[addr] = false;
-    }
+  /**
+   * @dev remove an address' access to this role
+   */
+  function remove(Role storage role, address addr)
+    internal
+  {
+    role.bearer[addr] = false;
+  }
 
-    /**
-     * @dev check if an address has this role
-     * // reverts
-     */
-    function check(Role storage role, address addr)
-        view
-        internal
-    {
-        require(has(role, addr));
-    }
+  /**
+   * @dev check if an address has this role
+   * // reverts
+   */
+  function check(Role storage role, address addr)
+    view
+    internal
+  {
+    require(has(role, addr));
+  }
 
-    /**
-     * @dev check if an address has this role
-     * @return bool
-     */
-    function has(Role storage role, address addr)
-        view
-        internal
-        returns (bool)
-    {
-        return role.bearer[addr];
-    }
+  /**
+   * @dev check if an address has this role
+   * @return bool
+   */
+  function has(Role storage role, address addr)
+    view
+    internal
+    returns (bool)
+  {
+    return role.bearer[addr];
+  }
 }

contracts/payment/PullPayment.sol

@@ -1,13 +1,13 @@
-pragma solidity ^0.4.18;
+pragma solidity ^0.4.23;
 
 
-import '../math/SafeMath.sol';
+import "../math/SafeMath.sol";
 
 
 /**
  * @title PullPayment
  * @dev Base contract supporting async send for pull payments. Inherit from this
- * contract and use asyncSend instead of send.
+ * contract and use asyncSend instead of send or transfer.
  */
 contract PullPayment {
   using SafeMath for uint256;
@@ -15,6 +15,22 @@ contract PullPayment {
   mapping(address => uint256) public payments;
   uint256 public totalPayments;
 
+  /**
+  * @dev Withdraw accumulated balance, called by payee.
+  */
+  function withdrawPayments() public {
+    address payee = msg.sender;
+    uint256 payment = payments[payee];
+
+    require(payment != 0);
+    require(address(this).balance >= payment);
+
+    totalPayments = totalPayments.sub(payment);
+    payments[payee] = 0;
+
+    payee.transfer(payment);
+  }
+
   /**
   * @dev Called by the payer to store the sent amount as credit to be pulled.
   * @param dest The destination address of the funds.
@@ -24,20 +40,4 @@ contract PullPayment {
     payments[dest] = payments[dest].add(amount);
     totalPayments = totalPayments.add(amount);
   }
-
-  /**
-  * @dev withdraw accumulated balance, called by payee.
-  */
-  function withdrawPayments() public {
-    address payee = msg.sender;
-    uint256 payment = payments[payee];
-
-    require(payment != 0);
-    require(this.balance >= payment);
-
-    totalPayments = totalPayments.sub(payment);
-    payments[payee] = 0;
-
-    assert(payee.send(payment));
-  }
 }

contracts/payment/SplitPayment.sol

@@ -1,6 +1,7 @@
-pragma solidity ^0.4.18;
+pragma solidity ^0.4.23;
+
+import "../math/SafeMath.sol";
 
-import '../math/SafeMath.sol';
 
 /**
  * @title SplitPayment
@@ -20,7 +21,7 @@ contract SplitPayment {
   /**
    * @dev Constructor
    */
-  function SplitPayment(address[] _payees, uint256[] _shares) public payable {
+  constructor(address[] _payees, uint256[] _shares) public payable {
     require(_payees.length == _shares.length);
 
     for (uint256 i = 0; i < _payees.length; i++) {
@@ -28,6 +29,35 @@ contract SplitPayment {
     }
   }
 
+  /**
+   * @dev payable fallback
+   */
+  function () public payable {}
+
+  /**
+   * @dev Claim your share of the balance.
+   */
+  function claim() public {
+    address payee = msg.sender;
+
+    require(shares[payee] > 0);
+
+    uint256 totalReceived = address(this).balance.add(totalReleased);
+    uint256 payment = totalReceived.mul(
+      shares[payee]).div(
+        totalShares).sub(
+          released[payee]
+    );
+
+    require(payment != 0);
+    require(address(this).balance >= payment);
+
+    released[payee] = released[payee].add(payment);
+    totalReleased = totalReleased.add(payment);
+
+    payee.transfer(payment);
+  }
+
   /**
    * @dev Add a new payee to the contract.
    * @param _payee The address of the payee to add.
@@ -42,29 +72,4 @@ contract SplitPayment {
     shares[_payee] = _shares;
     totalShares = totalShares.add(_shares);
   }
-
-  /**
-   * @dev Claim your share of the balance.
-   */
-  function claim() public {
-    address payee = msg.sender;
-
-    require(shares[payee] > 0);
-
-    uint256 totalReceived = this.balance.add(totalReleased);
-    uint256 payment = totalReceived.mul(shares[payee]).div(totalShares).sub(released[payee]);
-
-    require(payment != 0);
-    require(this.balance >= payment);
-
-    released[payee] = released[payee].add(payment);
-    totalReleased = totalReleased.add(payment);
-
-    payee.transfer(payment);
-  }
-
-  /**
-   * @dev payable fallback
-   */
-  function () public payable {}
 }

contracts/token/BurnableToken.sol

@@ -1,27 +0,0 @@
-pragma solidity ^0.4.18;
-
-import './BasicToken.sol';
-
-/**
- * @title Burnable Token
- * @dev Token that can be irreversibly burned (destroyed).
- */
-contract BurnableToken is BasicToken {
-
-    event Burn(address indexed burner, uint256 value);
-
-    /**
-     * @dev Burns a specific amount of tokens.
-     * @param _value The amount of token to be burned.
-     */
-    function burn(uint256 _value) public {
-        require(_value <= balances[msg.sender]);
-        // no need to require value <= totalSupply, since that would imply the
-        // sender's balance is greater than the totalSupply, which *should* be an assertion failure
-
-        address burner = msg.sender;
-        balances[burner] = balances[burner].sub(_value);
-        totalSupply = totalSupply.sub(_value);
-        Burn(burner, _value);
-    }
-}

contracts/token/DetailedERC20.sol

@@ -1,15 +0,0 @@
-pragma solidity ^0.4.18;
-
-import './ERC20.sol';
-
-contract DetailedERC20 is ERC20 {
-  string public name;
-  string public symbol;
-  uint8 public decimals;
-
-  function DetailedERC20(string _name, string _symbol, uint8 _decimals) public {
-    name = _name;
-    symbol = _symbol;
-    decimals = _decimals;
-  }
-}

contracts/token/ERC20.sol

@@ -1,16 +0,0 @@
-pragma solidity ^0.4.18;
-
-
-import './ERC20Basic.sol';
-
-
-/**
- * @title ERC20 interface
- * @dev see https://github.com/ethereum/EIPs/issues/20
- */
-contract ERC20 is ERC20Basic {
-  function allowance(address owner, address spender) public view returns (uint256);
-  function transferFrom(address from, address to, uint256 value) public returns (bool);
-  function approve(address spender, uint256 value) public returns (bool);
-  event Approval(address indexed owner, address indexed spender, uint256 value);
-}

contracts/token/ERC20/BasicToken.sol

@@ -1,8 +1,8 @@
-pragma solidity ^0.4.18;
+pragma solidity ^0.4.23;
 
 
-import './ERC20Basic.sol';
-import '../math/SafeMath.sol';
+import "./ERC20Basic.sol";
+import "../../math/SafeMath.sol";
 
 
 /**
@@ -14,6 +14,15 @@ contract BasicToken is ERC20Basic {
 
   mapping(address => uint256) balances;
 
+  uint256 totalSupply_;
+
+  /**
+  * @dev total number of tokens in existence
+  */
+  function totalSupply() public view returns (uint256) {
+    return totalSupply_;
+  }
+
   /**
   * @dev transfer token for a specified address
   * @param _to The address to transfer to.
@@ -23,10 +32,9 @@ contract BasicToken is ERC20Basic {
     require(_to != address(0));
     require(_value <= balances[msg.sender]);
 
-    // SafeMath.sub will throw if there is not enough balance.
     balances[msg.sender] = balances[msg.sender].sub(_value);
     balances[_to] = balances[_to].add(_value);
-    Transfer(msg.sender, _to, _value);
+    emit Transfer(msg.sender, _to, _value);
     return true;
   }
 
@@ -35,7 +43,7 @@ contract BasicToken is ERC20Basic {
   * @param _owner The address to query the the balance of.
   * @return An uint256 representing the amount owned by the passed address.
   */
-  function balanceOf(address _owner) public view returns (uint256 balance) {
+  function balanceOf(address _owner) public view returns (uint256) {
     return balances[_owner];
   }