Updated to Version 1.11.3-beta - bug fixes

Added Version 1.11.3-beta fixing a few issues:

• Issue 154 - Optimise performance
  • Started, added low/high graphics setting in menu to turn off particles and directional lighting, reduced some physics processes, forces FPS to 60 max
• Issue 253 - compress music
  • Fixed, one .wav to mp3 saving 20 MB on build
• Issue 245 - Turn down tyre slip noises
  • Fixed
• Issue 247 - Vehicle stuck upside down
  • Fixed
• Issue 249 - Add instructions for ballistic missile
  • Fixed
• Issue 246 - Fix clipping stuck through walls
  • Fixed