Also:
- Remove unused code

Use import QGroundControl 1.0 to get to it

Also much other cleanup/change

This allows for testing issues found on high dpi screen without needing
a high dpi screen. it does this by doubling the font sizes.

Plus more overall ui work

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

- Restructured a number of MissionItem properties as well

Plus lots of other cleanup

- MultiVehicleManager is a Qml friendly replacement for UASManager
- Vehicle is a replacement for both UAS and AutoPilotPlugin

Can now scroll to work on laptops and tablets. Plus many other changes.

Everything is now based off of default font pixel size