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
Addresses fixes #1871 by making `axis.set_scale` private and adding
a wrapper function with depreciation warning.
Have a workaround if a Python 3 user has pyparsing <= 2.0.0
Updated default quit keymap to include cmd+w so people running on OS X would have a native cmd+w to close the window.
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.
Fixes issue #1960. Account for right/top spine data offset on transform when doing spine.set_position(). Also includes a testcase for the data locations.
Improved comment for data spine transform adjustment - taken from mdboom.
figure: optionally configure automatic use of tight_layout
Added bullet to api_changes documentation on PR #1964
add test for automatic use of tight layout
Failing tests.
Fixes bug where linestyle always appears solid if linewidth is large enough
Fixes bug where if alpha is set and edgecolor='none', edges would still be rendered as black.

Also fixes test case result that hit this bug
Changes backends to support of independent face and edge alphas

Specifically, alters the base, AGG, PDF, PGF, SVG, Cairo, and Mac OS X
backends to better enable the use of RGBA color values for both fills
and edges. An explicit alpha attribute, if set, will override the
alpha channels of the color values.

Updates test results, which are now what would be expected.

Also fixes a couple bugs with handling of linestyles.
Add additional patch tests.
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
Added documentation of patch/alpha changes.