Update Gii model template.

Add namespaces and define use directives.
Update RBAC and add <initRbac> action in UsersCommand

Rename "admin" role to "administrator".
Updated BackEndController, StaticUserIdentity, SiteClosedFilter, UsersCommand, users/DefaultController, LogoutUnnecessaryUsersFilter and one view.
Add "moderator" role.

Update UsersCommand: add <initRbac> action.
Use it to synchronize RBAC information in database with information stored in /protected/modules/users/data/accessrights.php.

Added users/data/accessrights.php file with two roles.
Add showing user's roles in users/admin/users CRUD