(svn r6644) -Fix(r6637): remove inline to allow MSVC compilation
-Fix(r5124): Add aircraft.h to MSVC projects

(svn r6637) -Codechange: merged all (vehicle type)EnterDepot into VehicleEnterDepot()
This revealed duplicated code like aircraft lists got invalidated twice
Moved invalidation of the vehicle detail window to VehicleServiceInDepot() as it should always be updated when serviced

(svn r6529) -Fix r6513: [depot window] added missing switch in CcCloneVehicle()
The result of this missing switch was asserts in some cloning conditions (not all) (spotted by KUDr)

(svn r5124) Add IsAircraftInHangar{Stopped,}(), which supersedes CheckStoppedInHangar()
-Fix: Be more strict what it means for an aircraft to be in a hangar: It's not just being stopped on a hangar tile