Starship Battle update Ver. 0.9.0

Major update!
Notes:
- Singleplayer!!!!
- General bug fixes and quality of life improments. (remembering what class you played as last round, astroid generation, etc)
- Minor UI overhauls. (speedgauge, resizing of certain displays, etc)
- Complete revamp of the background. (new sprites, parallax, etc)

The obviously biggest change is the addition of a singleplayer mode to practice and compete in - this was added because well my friends don't always have time for me, but i still wanted to play, so i made a singleplayer mode.
The background was changed mostly to further increse visibility and for well asthetics