Fixes a bug in font family lookup.  Any font in the font alias
list (e.g. font.sans-serif) would be considered a perfect match whenever
the selected font alias is the first in the font.family list.  This
broke the priority ordering of font names.
Add test
Use assert_equal
No need to cast to floats with future division
BLD : adjust min six version to 1.3
Re-Generate legend, through apply_callback/Apply

If there is a legend, it is re-generated when "Apply" is clicked.
See Issue #2934:
Might have side effects.
matplotlib#2934
tacaswell: "However this will clobber any legend that is not the auto-magically generated one so it should probably also get a tick box to enable/disable the updating of the legend."
Tick box not included.
Added a checkbox for (re-)generating auto-legend

Checkbox added that controls if an automatic legend is re-generated, or generated for the first time.
This checkbox defaults to False, as it generates a simple legend when set to True, see matplotlib.pyplot.legend(), which clobbers any carefully handcrafted legend.
re-generate legend: re-use: ncol and draggable

Copy some properties from the old legend to the new (re-)generated legend.
If the old legend was draggable, the new one is now also.
The number of columns in the legend is passed on from to old legend to the new legend.
re-generate legend: fixes

Fixed crash if there was no previous legend.
Fixed ncol inheritance.
pep8 compliance

Ran pep8.py 1.5.6 (https://github.com/jcrocholl/pep8) over the code.
Fixed all complaints.
figureoptions.py is now pep8 compliant

*/matplotlib/backends/qt4_editor/figureoptions.py
now passes pep8 checks.
Fix for issue #2963
Image::resize will now raise a runtime error if the user passes in an invalid width or height.
BboxImage.make_image will now ensure that the width and height it passes to Image::resize are positive or zero.
BboxImage.draw now calculates the bottom left corner of its Bbox, rather than using the "first" corner of its Bbox.
BUG : improved input clean up in Axes.{h|v}line

 - passing in a (N, 1) shaped array as input causes the zipping to
   generate an extra dimension
 - closes #2197
 - use ravel + reshape to do shape validation + getting rid of
   extra dimension
Added a test for BboxImage with inverted corners.
Merge pull request #2771 from mdboom/fonts/fix-lookup-mechanism

Fix font family lookup calculation
Merge pull request #3014 from tacaswell/hline_vline_input_cleaning

BUG : improved input clean up in Axes.{h|v}line
mpl issue: #2974 - documentation corrected
Fix minor typo in customisation docs
avoid np.nan values in colors array returned by axes3d._shade_colors
Add a colorblind friendly heatmap.