* Improve encapsulation on Whitelist
* remove only
* update whitelisted crowdsale test
* Improve encapsulation on SignatureBouncer
* fix missing test
* Improve encapsulation on RBAC example
* Improve encapsulation on RBAC example
* Remove extra visibility
* Improve encapsulation on ERC20 Mintable
* Improve encapsulation on Superuser
* fix lint
* add missing constant