Replace fatals by warnings in CAircraftModelLoaderXPlane

The warning message is there in order to tell developers that one of the
rare cases not yet implemeneted were called. This should not cause
the application to stop.

refs #574, #582

src/blackmisc/simulation/xplane/aircraftmodelloaderxplane.cpp

@@ -460,7 +460,7 @@ namespace BlackMisc
 
                 // Flyable aircrafts are parsed by a different method. We don't know any aircraft files in CSL packages.
                 // If there is one, implement this method here.
-                qFatal("Not implemented yet.");
+                CLogMessage(this).warning("Not implemented yet.");
                 return true;
             }
 
@@ -474,7 +474,7 @@ namespace BlackMisc
                 }
 
                 // RW: I need an example of the file to properly implement and test it.
-                qFatal("Not implemented yet.");
+                CLogMessage(this).warning("Not implemented yet.");
                 return false;
             }
 
@@ -488,7 +488,7 @@ namespace BlackMisc
                 }
 
                 // RW: I need an example of the file to properly implement and test it.
-                qFatal("Not implemented yet.");
+                CLogMessage(this).warning("Not implemented yet.");
                 return false;
             }