adds asteroids! well, actually adds 1 visible asteroid and lots of invisible asteroids.
for some reason the visual representation of an asteroid and the physics location of an asteroid seem to disconnect and all asteroids share the same drawing shape.
adds lots of bad code for asteroids, once the display issue is fixed then the code can be cleaned.
 - createasteroidfield(numberhere) generates a field of asteroids of (numberhere) number. a single asteroid can also be generated. the asteroids are randomly generated with some help. i started creating a pure random asteroid until i realized that i was miss using math.random() and instead i need to come up with a smart way how to make a good random shape. the current way is just a cheap way to get unique shapes so they all don't look the same, but you will get some weird looking asteroids. some room for polish here.