adding a few keywords for fun
changed compiler so index.html not needed in this directory
changed compiler so index.html not needed in the app/templates directory
synchronized default values in canvas.coffee and base_module.coffee (todo: get rid of this 'redundancy')
allow for sliders to have negative values (got rid of the weird negations in the code)
support for new reset button
refactor base_module to support the various actions of the button (play, pause, reset)
ensure that the state of both balls is updated after a collision
now that the velocities within a module are the physical equivalent of the velocity in that frame of reference, we no longer need to be offsetting the velocity by the frame's velocity
fixed inconsistent default values and made playAll button use buttonAction instead of directly calling play() method