Plus lots of other cleanup

- Moved all MavManager functionality to Vehicle
- Updated all code to use Vehicle instead of MavManager
- Removed MavManager

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

- FirmwarePlugin is the new place for code which is specific to
firmware flight stack
- FirmwarePlugin currently supports flight mode apis
- Modify code to use new FirmwarePlugin support

I didn't realize TC for Ubuntu had GStreamer installed.

Everything is now based off of default font pixel size

Also check for writable settings in unit test runes

Sorting source and headers while at it.

Initial rendering of Waypoints