Renamed "Invalid" (airspace) to "custom"

Break apart string of classes into their own files as all in one file became unwieldy
Expose Airspace data in a QML ready format
Split global Airspace from AirMap (Only now I figured out the reason for the pure virtual root classes)
Refactored a bunch of things to make it consistent and/or obvious

Too complicated supporting both modes as editor becomes more complex

- You can now cancel parameter change
- Tablete friendly