refs #395, improvements for snapshot / restricted aircraft handling

* fixed isCurrentThreadCreatingThread and renamed to isCurrentThreadObjectThread (this check was never working), added 2 more thread checks
* changed remove aircraft function to return number of returned aircraft (like with the containers this allows to avoid unnecessary signals)
* removed unused function ps_recalculateRenderedAircraft() / SimulatorCommon
* using Queued airspaceAircraftSnapshot signal for binding (functor connect does not provide connection type)
* extened ASSERTs to check threads
* simulator: initial situation function with return value (success?)
* simulator: avoid unneccessary copy and provide correct rendered flag in add aircraft function

src/blackmisc/simulation/remoteaircraftprovider.h

@@ -108,6 +108,7 @@ namespace BlackMisc
                 std::function<void(const BlackMisc::Aviation::CCallsign &)>                   removedAircraftSlot,
                 std::function<void(const BlackMisc::Simulation::CAirspaceAircraftSnapshot &)> aircraftSnapshot
             ) = 0;
+
         };
 
         //! Class which can be directly used to access an \sa IRemoteAircraftProvider object
@@ -165,6 +166,6 @@ namespace BlackMisc
     } // namespace
 } // namespace
 
-Q_DECLARE_INTERFACE(BlackMisc::Simulation::IRemoteAircraftProvider, "IRemoteAircraftProvider")
+Q_DECLARE_INTERFACE(BlackMisc::Simulation::IRemoteAircraftProvider, "BlackMisc::Simulation::IRemoteAircraftProvider:IRemoteAircraftProvider")
 
 #endif // guard