ExitPoints now can be part of fly by or fly over orders
if exit point is the target point of those orders plane should be removed
Merge branch 'master' of https://github.com/SEPR13-SAW/Plane-Panic
removes duplicate calculations
generateFlightPlan() method added, generates flight plan randomly
LeaveAirspace.java order added to simplify flight plan generation and to make it easier for planes to leave airspace
Merge branch 'master' of https://github.com/SEPR13-SAW/Plane-Panic