Adding a spherical projection mode which will work at the poles and
+180/-180 line correctly. Not yet enabled since it has other issues to
be addressed.
Record the historical flight-path (by default, since last takeoff). Optionally display the flight-path in the map; other visualisations (e.g., an 'in-world' view) could also be created. Nasal API to follow so Canvas-map or FMS can show the same data.
Altitude and attitude (Euler angles) are currently recorded but not used anywhere.
Panning feature looked broken to some users since auto-center is enabled
by default which blocks panning. center-on-aircraft is now disabled
automatically when view is panned.
