matplotlib Code

Fix some compiler warnings

Fix documentation of path.simplify to reflect reality

added win32 release README

finished win32 release scripts

removed gw32 link flag that's not needed for mingw anymore

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 typo

more win32 build updates

only forward pick events to children with the same axes instance as the pick event inaxes method