Add support for compass priority

LinkInterface and Vehicle uses mutexes to synchronize writing bytes to the link instead of queued signals

More warnings cleanup
Android fix
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More
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Fix typo
Update android compiler warnings
Fix android compiler warnings
More android compiler warnings

Add support for Json file string translations

App messages now use simple modal message dialogs. Vehicle messages continue to use non-modal popup.

Fix Radio button problems

Fix RadioButton group problems. Rework RTL settings to match correct usage.

Remove ArduPilot Follow Me support from Stable

timer.start() and timer.stop() were breaking the 'running' binding of
the timer

Change follow to work above home altitude only

Support both relative and absolute FOLL_ALT_TYPE

This adds support for the new ArduSub 3.0 feature of automatically detecting
the thrusters directions and reverting the corresponding motor output if
necessary

Fix Follow X/Y calc from distance/angle

Disable closing app on last window close. This will close
the app on every widget spawned in QML that closes (MessageBox)

Advanced tuning hidden due to crash from Qt problem

Fix textRole usage for QGCComboBox

Update for missing params on rover

Follow page not showing up for Rover

Change jscript usage to make Qml compiler happy

Better handling of unsupported class/frame combinations

Update for 4.0 releases

ArduPIlot Follow Me setup

This is a bugfix due to changed signature in 3089da58

Enable ArduPilot motor testing

Use firmware version type, not vehicle type

Fix problems with ArduRover firmware parameter differences