port of GWTCanvas to python / pyjamas

[lkcl]

as part of the recent porting of GGhart to pyjamas, a massive
performance gain can be had by using SVG Canvas.  unfortunately, that
meant porting GWTCanvas to pyjamas as well.  this is also progressing
well:
http://pyjs.org/examples/gwtcanvas/

if anyone would like to help with the porting effort and with testing,
that would be great: please contact pyjamas-dev at groups.google.com.
the IE engine uses VML, and the GWTCanvas library takes care of
providing an SVG-like interface to VML (which is rather cool).

l.