Alternative to #2431: Decode the filenames returned from fontconfig in
the filesystemencoding.  Fix a number of buglets that did not allow
fonts with non-ascii filenames to be opened.  This involves taking
advantage of code already in FT2Font to use unicode filenames, and
encoding the filenames before passing into ttconv.
Just skip a file if its filename can not be decoded
Added check in autoscale_None for completely masked pcolor plots.
Fix MacOSX backend post-six transition
Use the --format argument to fontconfig so we don't have to parse
anything complex ourselves.
Fix failing mathtext tests.
Only set `use_2to3` on Python 3.
fixes issue with using transparency for the figure patch and
being able to see shadows of previous draws underneath.

see: http://stackoverflow.com/questions/18944561/matplotlib-pyqt4-transparent-figure

Added some documentation to `paintEvent`
Better error handling with font can not be loaded by macosx backend
Merge pull request #2449 from tacaswell/qt4_clear_before_draw

Qt4 clear before draw
Merge pull request #2446 from mdboom/old-distribute

Don't set use_2to3 unless we have to.
Updated gitignore to exclude build files from the examples.
Merge pull request #2455 from pelson/gitignore_update

Gitignore update
Skip CGContextSelectFont if font lookup fails
Merge pull request #2433 from mdboom/unicode-font-filenames

Handle Unicode font filenames correctly/Fix crashing MacOSX backend
Hide the .cached member of Text so it doesn't get documented.
pep8 clean up (file seems to have been created with indentation of 3
spaces!)
a bit more pep8 work
Add API change note.
Merge pull request #2457 from mdboom/private-members

Privatize Text.cached