cvs update

I just committed several changes to CVS. Most notably, I
changed the way edge versus face draws are done at the backend level,
as discussed earlier.

For the Renderer methods draw_arc, draw_rectangle and draw_polygon,
the signature is

  gc, faceColor, ....

rather than

  gc, fill, ....

faceColor is any legal matplotlib format string. To convert this to
an RGB, call backend_bases.arg_to_rgb. See GD, PS and GTK backends
for several approaches to handling edge and face calls. These (and
other minor) changes more than double the speed of pcolor in the GTK
backend and significantly reduce the size of pcolor PS output.

Other comments pertinent to the WX backend

  - backend writers should no longer need to define figure text.
    Everything is handled by Figure base class

  - artist clipOn is now a protected attribute _clipOn. Use
    set_clip_on to change it

I've pretty much fixed all the known frontend CVS bugs (scatter bug,
legend bug) and finished the ports of GD, PS and GTK backends to the
new API. Let me know if you find anything misbehaving.

John Hunter