Bug fixes

Changes made in this version:
- Fixed a bug that added empty airplanes into character selection
- Fixed an online bug that didn`t let people play with customized airplane
- Fxxed a bug that was crashing the game after couple of races
- Shen no longer has inverted jet engines
- Shen and Shark airplanes now have a little bit more decceleration
- Splinter airplane gained few max velocity points