(similar to remote aircraft provider)
* removed references
* made own aircraft context thread safe (reg. own aircrat data)
* removed the read only versions of the provider
* adjusted consuming methods
* renamed some functions ("ownAircraft...") to avoid ambiguity (with remote aircraft)
* access via provider, access now possible also beyond the scope of interpolator
* will be used in (to be written airpace analyzer)
* renamed some member functions as required
* fixed some asserts / Doxygen comments
* adjusted unit tests
* added vtolAircraft flag for interpolator, not fully used everywhere
remarks: update signals for parts / situation still only needed in XP driver
