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/fs9/simulator_fs9.h

@@ -74,8 +74,6 @@ namespace BlackSimPlugin
             //! \copydoc ISimulator::isSimulating
             virtual bool isSimulating() const override { return isConnected(); }
 
-        public slots:
-
             //! \copydoc ISimulator::connectTo()
             virtual bool connectTo() override;