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)

Added an "unavailable" icon for when no vehicle is connected
Toggle restriction overlays (map) on/off based on the airspace widget being expanded/collapsed respectively

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

All settings wired and persistent
Cleanup non Airmap builds

Eliminated flight widget "states"
Define flight widget top margin (plugin options)

Clarify the title of the "Video Stream" panel (instead of just "Video")

On large/high DPI screens, the whole UI scales nicely when increasing the
font size, except for the attitude widget, that was limited to 200 pixels.

Fixed a pile of bugs as well

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

qgcView was coming through null causing widget dialog to not pop up