Added XConverted.uml files to git ignore
Prepares IL for complex input parameter support

Still requires fUML Object_ to Java Object transformation (no
transformator implemented yet)
Adds test for inherited CallOperationAction calls
Adds new extended Vehicles library (VehiclesWithAirplane)
Adds Activity for new Vehicles library (airbusExample)
Adds test for new Vehicles library (airbusExample)