r3

Minor release to sync with npm publication. Not meant for production, but it's hardly going to screw much up if you do.

A few additions:

• Basic event model ('redraw' on each update)
• Rudimentary API efforts (don't get too attached)
• Simplified constructor
• Can optionally track arbitrary page element instead of mouse

Issues

• Uses JS features not supported in some browsers
• Tracking loses it in certain browsers under certain setups
• Gets very slow when working with sufficient elements