matplotlib Code

added rc param axes.unicode_minus

removed deprecated example

moved fill_between to axes/pyplot method

updated api for fill_between_where and span_where

renamed fill where examples

generalized fill between poly collection

added some helper functions for poly collections and masked regions

patches: allow partial rings with Wedge

update backend_driver for new location of two_scales.py

Include output images in examples in documentation.
Add "-*- noplot -*-" markers to examples where we don't want that.
The "plot" documentation directive now takes a path relative to the doc/ directory, not doc/pyplots.