refs #395, signatures for max.aircraft and max.range

(!) This in an intermediate step, the feature is not yet fully operational

* max distance for rendering as simulator property
* set max distance / aircraft from GUI

As result of the latest meeting
* changed CCallsignList to CCollection
* fixed some warning with elevated compiler settings (e.g. removed qint values -> int)

src/plugins/simulator/xplane/simulator_xplane.h

@@ -58,7 +58,6 @@ namespace BlackSimPlugin
             //! \copydoc BlackCore::ISimulator::getIcaoForModelString
             virtual BlackMisc::Aviation::CAircraftIcao getIcaoForModelString(const QString &modelString) const override;
 
-        public slots:
             //! \copydoc BlackCore::ISimulator::connectTo
             virtual bool connectTo() override;