-fixes #3023

Deleting old map tile disk cache if one is found.

Remove zoom support

Pull multiVehicleManager from QGroundControl

Turn off screen sleep if Vehicle connected

Bugs causing it to not be able to un-zoom.

Support user configurable unit conversion

Unit conversion for FactGroup and Mission Items

Reorder vehicle components

Better param reset for APM compass cal

Allow armed setup for Safety/Tuning

Fix some control width problems

Support for third compass calibration

Flash: Correct return after error

Fix ArduPilot compass cal

Fix #2987: QGroundControlQmlGlobal.h: flightMapZoom should be a doubl…

Note that a change in zoom signals a `zoomLevelChanged` event; this in turn triggers `FlightDisplayViewMap` which sets the property changed in this commit to
```
onZoomLevelChanged: QGroundControl.flightMapZoom = zoomLevel
```

This triggers the following message in Application Output: `onZoomLevelChanged: QGroundControl.flightMapZoom = zoomLevel`.

This was the case before and after this fix, I don't know if that's a real issue though

DO_JUMP fix

Add Guided mode support

PX4_CUSTOM_MAIN_MODE consistency