activeVehicle - >_activeVehicle
caused the virtual joystick to malfunction

Refactor/fixes for ProximityRadar and friends

Clean up references to MainRootWindow globals

Fix positioning at high scaling

- add NOTIFY for distanceSensor property
- add DistanceSensorReadingsChange() callback prototype

- revert excessive NOTIFY
- adding MaxSensor into DistanceSensor frame handling

- add proximity radar view in map view
- add proximity radar view in video view

change distance label positioning in video view

clean up unwanted comments

- space up proximity sectors
- revert unwanted changes in qgroundcontrol.qrc

squashed commits

Unified photo/video control which works with mavlink cameras and just video stream

Press and Hold on Arm will change it to Force Arm

Split into Views and Tools

Telemetry Values bar at center bottom

Move GuidedActionsController references to global

Fix ROI, Orbit, Goto handling

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

Rework handling of fw/vehicle type with respect to conflicts with actual vehicle types.

Cherry pick virtual joystick fix from Stable

Remove old action list code

ToolStrip rearchitecture for encapsulation and customization

Re-architect toolbar for better customization capabilities. Also use less real estate.

Rework Fly View into separate layers which can be customized at each layer.

More FlyView encasulation. Make QGCPipOverlay completely self contained

More work on encapsulation in Fly View

Fly View: Move business logic inside controls

Major rework to support terrain profile display and terrain collision reporting

Fix display of Continue Mission/Change Alt after Pause

Mavlink terrain protocol support

Put back ToolStrip titles which were mysteriously removed

added function to FlightView to show the checklist if switching views from a view other than FlightView and if checklist should be shown