Changelog:
- Added a sound menu with adjustable volumes.
- Minor adjustments:
- Game saves after completing a scenario, to avoid losing progression in case the autosave on exit fails.
- Planes won't backtrack anymore after landing at London City, because planes can use a taxiway in real life.
- For custom airports, the wake turbulence minima can be adjusted. See the 'wake' property in the [airspace] section of example.txt.
- Bug fix for departures that did not request further climb even when they were flying at a too low altitude.