RightManager: Server right manager has a mapObject function. Yet, on the client side there is none. However, a full mapObject function is not required. Since we store some information locally we need to make sure that at least types are mapped correctly.

Introduced a mask parameter for registerRight. If set, we can use this function if a masked object is supported by the right manager.

Minor changes to the right manager on the server side.
Right manager: Making use of the mask parameter for subroom and paperspace.

General object: Added the mask parameter to the registerRight shortcut.
Right manager UI: Since the manager role is not deletable, their rights cannot be changed either.
Merge branch 'develop' of github.com:winfel/wa_knowledge_structuring into develop