Make all argument to AirMap queries based on what the screen shows (bounding rectangle and/or radius), respecting the limits imposed by AirMap.

AirspaceManager is now exposed by QGroundControlQmlGlobal instead of Vehicle (available all the time)

An rather unfruitful attempt at consolidating Advisories and Airspaces (they are both arrays of Airspaces). No such luck as they vary wildly. In the end, I'm now exposing the restrictions (Polygons) directly (and inherently) instead of copying them.
Tweaked polygon overlay colors and borders.

Handled "airspace visible" state (not done)
Adjusted restriction map items color and opacity
Added/Updated icons for airspace traffic
Adjust colors for text over maps

Move all airmap related stuff to its own directory

- add multi-vehicle support: each vehicle has now a per-vehicle AirMap
  object that takes care of flight creation, traffic & telemetry
- add a base class API layer so that the interface between QGC and the
  AirMap implementation is clear, and easier to change
- removes polygon upload to vehicle (needs a better solution)

Make AirMapController as part of a Vehicle rather than a creatable QML instance. This is ultimately linked to a vehicle and not the view. Eventually a lot of the code currently in AirMapManager will have to come here as well so the data persists with a vehicle. AirMapManager should only handle the global aspects.
Added a temporary indicator right below the toolbar. It's only visible if a permission (of any kind) exists. I need to understand better how this works before coming up with a more permanent solution.
Restored toolbar to its original state (brand logo and whatnot)

Also rename QmlPageInfo to QmlComponentInfo to cover more use cases

Used to display items associated with Flight Plan on Map

- Don't allow goto click while other guided ui is visible
- Use NoMouseThroughRectangle for guided ui popups
- Better visuals for goto indicator in map

Update the user model to a single controller instead of multiple

Added top/bottom alignment state to map scale
Allow disabling instrument widget altogether
Added an otherwise redundant row to PlanToolbar so it matches the same button position as the main toolbar
Fixed typo (Math.max()) in ScreenTools
Fixed Javascript Exception in OfflineMap
Increased the import window size in OfflineMap
Added function to MainWindow to disable toolbar for a truly modal dialog
Added code so clicking on an open toolbar indicator will cause it to close

Plus low battery announce changes

* Map type now set from General settings
* No map type control in maps