refs #811, airports default implementation

* if no sim data are available use reader data
* merge airport data for FSX
* Added "network" in .pro (needed for network classes such as readers)

src/plugins/simulator/xplane/simulatorxplane.cpp

@@ -351,6 +351,7 @@ namespace BlackSimPlugin
 
         void CSimulatorXPlane::ps_setAirportsInRange(const QStringList &icaos, const QStringList &names, const BlackMisc::CSequence<double> &lats, const BlackMisc::CSequence<double> &lons, const BlackMisc::CSequence<double> &alts)
         {
+            //! \todo restrict to maxAirportsInRange()
             m_airportsInRange.clear();
             auto icaoIt = icaos.begin();
             auto nameIt = names.begin();