* 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