Much better mission->kml conversion support

Use global palette

Add support for isTakeoffCommand MissionCommandUIInfo

Fix typo

Add global palette object to QGroundControlQmlGlobal for generic usage

Remove unnecessary includes of QGroundCotrolQmlGlobal.h

 - UVify Core board support is implemented.

Guard against UI Info not available causing crash

Always how command description. Better support for VTOL Takeoff. New help text for altitude on Land commands.

Change some descriptions to be more understandable/correct. Change some Heading->Yaw labels. Use new isLandCommand setting.

Fix file extension appending