* rename ERC20 to IERC20

* move ERC20.sol to IERC20.sol

* rename StandardToken to ERC20

* rename StandardTokenMock to ERC20Mock

* move StandardToken.sol to ERC20.sol, likewise test and mock files

* rename MintableToken to ERC20Mintable

* move MintableToken.sol to ERC20Mintable.sol, likewise test and mock files

* rename BurnableToken to ERC20Burnable

* move BurnableToken.sol to ERC20Burnable.sol, likewise for related files

* rename CappedToken to ERC20Capped

* move CappedToken.sol to ERC20Capped.sol, likewise for related files

* rename PausableToken to ERC20Pausable

* move PausableToken.sol to ERC20Pausable.sol, likewise for related files

* rename DetailedERC20 to ERC20Detailed

* move DetailedERC20.sol to ERC20Detailed.sol, likewise for related files

* rename ERC721 to IERC721, and likewise for other related interfaces

* move ERC721.sol to IERC721.sol, likewise for other 721 interfaces

* rename ERC721Token to ERC721

* move ERC721Token.sol to ERC721.sol, likewise for related files

* rename ERC721BasicToken to ERC721Basic

* move ERC721BasicToken.sol to ERC721Basic.sol, likewise for related files

* rename ERC721PausableToken to ERC721Pausable

* move ERC721PausableToken.sol to ERC721Pausable.sol

* rename ERC165 to IERC165

* move ERC165.sol to IERC165.sol

* amend comment that ERC20 is based on FirstBlood

* fix comments mentioning IERC721Receiver