Remove depency on screen for height/width
Remove dependencies on screen object
Turn screen global into a module
About halfway through refactoring screen

Moved screen to board.js, changed name. pushed most things out of the run.js
into the board where they belong. broke a lot of stuff that needs fixed,
starting with collisions.
Add cass to contributers
No longer maintaining the ball.js code
Huge change, redid collisions

Okay so collisions work again mostly. The objects currently just check to see
if an object is in the other tile at all rather than trying to collide with it
because that is currently broken. Not sure why
Added some comments on to implement collisions