Fix of macosx text rendering truncation with edit 
of _macosx to overcome change in Py_UNICODE size
that occurred in Python3.3
Rollback of error introduced in 
GraphicsContext_draw_image from previous commit.
Fix #1885: Text clipping should always set the patch to the axes, regardless of the state of the clip_on kwarg, so that clip_on can be toggled after the fact
re-added lines to make sure that `bottom` and `left` are not None in
the case of `log=True`.  If this is not done, there will be type
exceptions.

Issue #1882
simplified logic related to bottom=None and log in `bar`
Added a test for #880.
Addresses fixes #1871 by making `axis.set_scale` private and adding
a wrapper function with depreciation warning.
All changes wrapped by preprocessor directive PY33 to make backward compatible.
All changes wrapped by preprocessor directive PY33 to make backward compatible.
Wrapped #ifdef to make backward compatible.
Have a workaround if a Python 3 user has pyparsing <= 2.0.0
Spelling and import tweaks it axis.py.
wx backend should not attempt to render jpeg/tiff if PIL is present.

If PIL is present, the wx backend needs to allow the base class to get the
job done for print_jpeg and print_tiff, instead of trying to take over
duties itself.
Tidy up the matplotlib.__init__ documentation.
figure: optionally configure automatic use of tight_layout
add test for automatic use of tight layout
Take Image object's alpha attribute into account when compositing multiple images together.
Fix Cairo backend so Images are actually visible for output formats other than PNG.
Add a test case for compositing images with an alpha attribute
Updated test, and added a check for tuple length