the solution is to introduce a superinterface
and let Dispatcher augment that with the specific parts.
This way, the Job planning only has to rely on the
rather generic stuff (TimeAnchor, FrameCoord)
NOTE: this commit makes the whole JobPlanning machinery
compilable for the first time!
..the Idea is to rely on some kind of service,
to break the cyclic dependency with the Dispatcher.
But I seem unable to find a natural location or
concept to house that service.
