- Remove permission logic on command side; make PermissionsManager handle checks for all CommandSender objects (not only Player), cf. #314
- Remove unnecessary redundancies in passed arguments ("command references" that can be inferred from the FoundResult)
- Extend FoundCommandResult to represent all possible error cases
- Move permissions responsibilities from command to permissions (remove some logic from CommandPermissions, add DefaultPermission enum to permissions package)
- Start possible interface for the future per-permission system implementations of permissions managers