Closed beta v0.8.5 out now, with track generation and opponent balance fixes

- Prevent track overlaps at Start / Finish line
- Overhaul of track generation algorithm to reduce hairy overlap situations
- Adjust opponent car strength balance in Campaign. Difficulty will affect
chance and amount of stronger opponents.
- Configurable corner cutting penalties for Quick Race
- Closed Campaign tracks will always have at least 2 laps
- Visual improvements for race results panel
- Fix for tooltip positioning
- Fix a bug that was setting wrong difficulty for Campaign races