Merge branch 'master' into feature/implement_erc721_standard

contracts/token/BasicToken.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.

contracts/token/BurnableToken.sol

@@ -22,7 +22,7 @@ contract BurnableToken is BasicToken {
 
     address burner = msg.sender;
     balances[burner] = balances[burner].sub(_value);
-    totalSupply = totalSupply.sub(_value);
+    totalSupply_ = totalSupply_.sub(_value);
     Burn(burner, _value);
   }
 }

contracts/token/CappedToken.sol

@@ -24,7 +24,7 @@ contract CappedToken is MintableToken {
    * @return A boolean that indicates if the operation was successful.
    */
   function mint(address _to, uint256 _amount) onlyOwner canMint public returns (bool) {
-    require(totalSupply.add(_amount) <= cap);
+    require(totalSupply_.add(_amount) <= cap);
 
     return super.mint(_to, _amount);
   }

contracts/token/ERC20/ERC20Basic.sol

@@ -7,7 +7,7 @@ pragma solidity ^0.4.18;
  * @dev see https://github.com/ethereum/EIPs/issues/179
  */
 contract ERC20Basic {
-  uint256 public totalSupply;
+  function totalSupply() public view returns (uint256);
   function balanceOf(address who) public view returns (uint256);
   function transfer(address to, uint256 value) public returns (bool);
   event Transfer(address indexed from, address indexed to, uint256 value);

contracts/token/MintableToken.sol

@@ -32,7 +32,7 @@ contract MintableToken is StandardToken, Ownable {
    * @return A boolean that indicates if the operation was successful.
    */
   function mint(address _to, uint256 _amount) onlyOwner canMint public returns (bool) {
-    totalSupply = totalSupply.add(_amount);
+    totalSupply_ = totalSupply_.add(_amount);
     balances[_to] = balances[_to].add(_amount);
     Mint(_to, _amount);
     Transfer(address(0), _to, _amount);