- Add easy default methods on PermissionHandler interface (override whenever there's a better way!)
- Change getGroups() signature to return a Collection instead of a List
- Move permission check inside PurgeTask to perform it with OfflinePlayer objects instead of lowercase names
- Move purge members into child "purge" package
- Unify online and offline default permission behavior in DefaultPermission
- Change permission handler to retrieve the services it needs, instead of getting them from the PermissionsManager
- Reduce visibility of some methods
- Add Reloadable interface
- Evaluate permission for DefaultPermission on the enum itself
- Remove boolean default from PermissionHandler for hasPermission()
- Remove some unused / intermediary hasPermission() flavors in PermissionsManager
