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
Fix inkscape install errors on Travis
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
Restored inkscape installing on travis-ci.
Merge pull request #1890 from pelson/travis_inkscape

Restored inkscape installing on travis-ci.
simplified logic related to bottom=None and log in `bar`
Fix gen_rst.py to use the correct encoding even on Python 2.
Fix #1894: Composite images do not have a transparent background
Merge pull request #1894 from mdboom/image/composite_background

Fixes background coloring of multiple images on the same axes.
Merge pull request #1897 from mdboom/doc/encoding_gen_rst

Fix documentation build failure (unicode error in generate_example_rst)
Corrected a wrong numpy record name in documentation. adjusted_close in parse_yahoo_historical doesn't exist, the author mean aclose
Make the travis output slightly quieter, particularly when installing dependencies.  Add Python 3.3 to the tests.
Merge pull request #1965 from mdboom/simplify-travis

Make the travis output quieter on v1.2.x
Update pngsuite.png test image
Fixed failing bbox_inches='tight' case when a contour collection is empty.

Conflicts:
	lib/matplotlib/tests/test_collections.py
SubplotBase._make_twin_axes always creates a new subplot instance. Fixes #1957.
Skip over zero-length subpaths.  Calculate for each subpath and then "or" those results together.
Fix #1973: offset_position == 'data' is not respected by point_in_path_collection
Escape XML comments correctly when writing out SVG.  Turns '--' into '- -'
Merge pull request #1967 from mdboom/svg-comment-escape

svg double hyphen in plot title --