Yoric/bouncer — pull request #66 by Yoric (2013-12-13 17:36:14+00:00)
Title: Issue #59: Using CSS for various kinds of balls

We now use CSS classes for the various kinds of balls.
Other changes along the way:
- moved all the CSS from style.css to balls.css;
- fixed a off-by-one bug in `Ball.prototype.changeBallColor`;
- added animations for the transitions;
- made the ball kinds a little more different from each other.