This way we don't need macro-magic to deal with
different operating systems and compilers.

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

We just wanna move some code from QThread, from private
to public, se can use using:: for that.

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

This shouldn't break a thing on other linux boxes that compiles
fine.

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

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

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