Merge pull request #285 from frangio/feature/token-timelock

Add a TokenTimelock contract

contracts/token/TokenTimelock.sol

@@ -0,0 +1,41 @@
+pragma solidity ^0.4.11;
+
+
+import './ERC20Basic.sol';
+
+/**
+ * @title TokenTimelock
+ * @dev TokenTimelock is a token holder contract that will allow a 
+ * beneficiary to extract the tokens after a given release time
+ */
+contract TokenTimelock {
+  
+  // ERC20 basic token contract being held
+  ERC20Basic token;
+
+  // beneficiary of tokens after they are released
+  address beneficiary;
+
+  // timestamp when token release is enabled
+  uint releaseTime;
+
+  function TokenTimelock(ERC20Basic _token, address _beneficiary, uint _releaseTime) {
+    require(_releaseTime > now);
+    token = _token;
+    beneficiary = _beneficiary;
+    releaseTime = _releaseTime;
+  }
+
+  /**
+   * @dev beneficiary claims tokens held by time lock
+   */
+  function claim() {
+    require(msg.sender == beneficiary);
+    require(now >= releaseTime);
+
+    uint amount = token.balanceOf(this);
+    require(amount > 0);
+
+    token.transfer(beneficiary, amount);
+  }
+}