* Consolidted ERC20 Interface and Implementation Files

* Fixed CanReclaimToken's tests to use StandardTokenMock instead of BasicTokenMock

* Changed token's variable type in TokenTimelock to ERC20

* Merged the StandardBurnableToken with BurnableToken since it now inherits from StandardToken; Fixed TokenTimelock so it uses SafeERC20 for ERC20

* Fixed variable type for _token in TokenTimelock constructor

* Fixed linting warning in BurnableToken

* Added back burnFrom tests.