getting dimensions from canvas
renderer gets width and height from element
removed old CLEAR constant
added material, sort of working, lost variable mass rendering
working with materials
walls have material now
removed a bunch of updateUserSettings overhead
restitution updating
startup reorg
implemented Particle.wrap(), gave Particle.attractSquare() a minimum distance
implemented smarter mouse gravity
mouse gravity no longer fades
moved demo specific functions out of Particle class
implemented a more generic renderer
better generic renderer