Merge pull request #3 from aybabtme/master

Partially refactored SpaceShip.java
WIP: Refactored entity
WIP: Game and InputHandler are now singletons
WIP: Stupid entity
WIP: Refactor space ship and bullet
Removed center point
WIP: Refactored circle
Refactored pentagon. I think I'm done
Merge branch 'refactoring'
Added rotate method, got rid of fire method
Added some innertia to ship (need to improve), hid the other shapes
Changed entity to interface
Game focuses when it starts, cleaned up spaceship a bit (added some constants, removed calls to toRad, commented)
Made dimensions public
Space ship and bullets wrap around, bullets expire after time
Bigger canvas, centered
Slower bullets
Added asteroid
Added small variation to speed
Added two more asteroids, they appear at random locations now