* Improve encapsulation on ERC165
* Improve encapsulation on ERC20
* Improve encapsulation on ERC721
* Add tests, use standard getters
* fix tests
* Fix lint
* move interface ids to implementation contracts
* Do not prefix getters
* rename proposals directory to drafts directory
* move TokenVesting and SignatureBouncer to drafts/
* rename BouncerMock.sol to SignatureBouncerMock.sol