Changelog Version 0.8

Heyo, just a few small changes:

• Added "confirm quit" screen
• Added background behavior such that certain backgrounds can be enabled and disabled at runtime (has currently only effect on asteroid fields)
• Implemented basic level select system (accessible trough pause menu by pressing north button on controller or L on the keyboard)
• added simple keyboard controls instructions
  
• added star counter (early stage, but better than having UI Text "Score: x")