mobimol v0.4

the previous version (v0.3) didn't survive long. get the latest at:
http://tovganesh.googlepages.com/mobimol.py

change log:
- fixed lots of bugs. one notable one is the call to math.acos() in findAngle(), which i feel is a bug in the implementation of acos rather than my code.
- the other notable change is that the painting technique has changed from endless loop to canvas.redraw_callback method, this has greately reduced the cpu cycles mobimol consumes.
- apart from the H₂O coordinates provided by [cyke64] on nokia forums, you may also obtain benzene(C₆H₆) coordinates from here http://tovganesh.googlepages.com/benz.xyz.

enjoy!