cartalyst/sentry — pull request #205 by iainconnor (2013-06-05 16:32:15+00:00)
Title: Break cache of user groups and permissions once a group is added/removed to that user

As an example, if you do `$user->addGroup($group);` and then `$user->getMergedPermissions();`, you won't get the permissions changed by that `->addGroup` because those properties are still cached. This change breaks that cache when a group is added or removed.