matplotlib Code

modifications to examples/docs to get them to build for the website

removed reserved name "as" from some examples

update doc strings to point to new fill between demos

update changelog

add support for bz2 files per sf support request 2794556

fixed a doc tutorial url

fix typo in axes_grid/clip_path.py

Tweak John's change to handling of rgba arrays

Try to improve the cursor readout and status message.
This could be done better with changes to the backends.
The status (pan/zoom etc) should be indicated via the
state of the buttons, e.g. using radio buttons, rather
than by printing text. The readout should be positioned
to minimize jumping around of the text.

Update CHANGELOG