Implement our own CombBox from scratch
Implement our own CombBox from scratch

On 5.7 and 5.8 somethings this would happen:
* The menu would be ordered incorrectly due to bug in Instantiator
* The menu would be positioned incorrectly

Hunter522/qgroundcontrol,ethz-asl/qgc_asl,ethz-asl/qgc_asl,ethz-asl/qgc_asl,ethz-asl/qgc_asl,Hunter522/qgroundcontrol,Hunter522/qgroundcontrol,Hunter522/qgroundcontrol,ethz-asl/qgc_asl,Hunter522/qgroundcontrol,Hunter522/qgroundcontrol