Commits
- add GXLatLonQuad #3605 (Michael Oborne)
- add bitmap support #3605 (Michael Oborne)
- add kml tempdir #3605 (Michael Oborne)
- add kml groundoverlay loading #3605 (Michael Oborne)
- add support for LatLonBox #3605 (Michael Oborne)
- rewrite MessageShowAgain #3591 (Bob Long)
- fix zero-alt warning for ArduPlane #3591 (Bob Long)