matplotlib Code

added JJ's F/C two scale example

Spine is now derived from Patch

make default argument to Axes.get_xaxis_transform() not raise error

I made this a separate commit from the previous one because it may be
useful to see the errors that arise if get_xaxis_transform() or
get_yaxis_transform() are called with no arguments. This would allow
one to figure out which code paths are calling these methods and fix
them if needed rather than silently partially succeeding.

Arbitrary spine placement

Fix broken example.

Fix problem with polar grid lines by specifying the number of interpolation steps on a per-Path basis. This isn't really a public API -- it is intended for internal use only.

added compound path demo

added compound path demo

Fix join style bug in pdf.

Fix logo-generation script to have rounded polar bar plots.