It was using wrong size variable (and consequently too big)

Instead us a Toolbox concept which hangs off of QGCApplication

When you selected via the Menu to go to Fly Mode, the QML
toolbar didn't followed the option, and if you selected
via the menu to go to all the three possible views (setup,
fly and plan) the menu would be all-selected.

This tries to keep consistency of things.

Signed-off-by: Tomaz Canabrava <tomaz.canabrava@intel.com>

Plus lots of other tweaks to ui for visuals

Mostly accomplished by delay loading Qml elements

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

- 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

Also restructured some toolbar positioning QML to handle resizing.

Everything is now based off of default font pixel size

Also adding a constant for the font size in SensorComponent.

If Facts are referenced from FactPanelController, we need to reference
count the AutoPilotPlugin such that it doesn’t get destroyed until
after the FactPanelController is destroyed.