Mostly accomplished by delay loading Qml elements

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

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

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

Also restructured some toolbar positioning QML to handle resizing.

Everything is now based off of default font pixel size

Initial rendering of Waypoints

- All resources are either under src or under resources dirs
- Removed files top level directory
- Move flightgear files to top level dir

Use default font wherever possible. Where that doesn’t work, use
ScreenTools::dpiAdjustPointSize.

Moved update canvas signal to perspective load instead of hooking it to the paint event.
Added an "S" as the unit for the number of cells fact (as in 4S).