Fixing a lot of ugly hacks and integrating interface for new functionalities

A lot of functionality (like re-publishing logged designators) is now part the actual C++ beliefstate logger. Also, support for new functionalities is introduced (like setting the meta data for an experiment). Parts of the hooks that are called during task execution are already replaced by the more CRAM-like `define-hook` callbacks. More to come.
Replaced a `tf:wait-for-transform` by a more dynamic structure that refreshed the poses' timestamp as needed.

This might seem like a hack, but for the case supplied the timestamp does not really matter (as timing information is determined separatly for the movement). So, this is just fixing the code from hanging in a place while waiting for a transform forever.
Made the code a bit nicer.