Mostly accomplished by delay loading Qml elements

This reverts commit 86f29adf.

This is in preparation for full Qml main window

Main toolbar: Clearly indicate that we do not have battery indication (and the battery is not just flat at 0.0V

- Delete all old map code

- select active vehicle
- arm/disarm
- select flight mode

Also:
- Remove unused code

Too complicated supporting both modes as editor becomes more complex

These use OpenGL implementation which prevented moving to ANGLE
support. Since they are rarely used they are being remove instead of
being upgrade.

These use OpenGL implementation which prevented moving to ANGLE
support. Since they are rarely used they are being remove instead of
being upgrade.

- New MissionManager
- Plumb MissionManager through MissionEditor
- Mission Editor supports get/set

- Restructured a number of MissionItem properties as well