refs #643, moved aircraft model icon loading to model class

* removed iconForModel from interface and aircraft config parser
* CPixmap support for loading pixmap from file
* Access to model of model set loader by model string
* icon path as member of CAircraftModel

src/blackmisc/simulation/aircraftmodelsetloader.h

@@ -50,8 +50,13 @@ namespace BlackMisc
             BlackMisc::Simulation::CAircraftModelList getAircraftModels() const;
 
             //! Count of loaded models
+            //! \threadsafe
             int getAircraftModelsCount() const { return getAircraftModels().size(); }
 
+            //! Model for given model string
+            //! \threadsafe
+            BlackMisc::Simulation::CAircraftModel getModelForModelString(const QString &modelString) const;
+
             //! Which simulator is supported by that very loader
             const BlackMisc::Simulation::CSimulatorInfo &getSimulator() const;