overloaded `_make_twin_axes` on `LocateableAxesBase` so that twinx and
twiny will work.
Merge pull request #2623 from efiring/include_order

setupext: put pkg-config -I, -L, -l locations at the head of the list
Small typo in the license.
Added option to show/hide Source link in plot_directive
Added html to option name
Merge pull request #2644 from arokem/license_typo

Small typo in the license.
Merge pull request #2644 from arokem/license_typo

Small typo in the license.
Update backend_webagg.py

Change WebAgg backend to handle stale figure UI controls in the browser
Update mpl.js

We are generating 'ReferenceError: figure is not defined' when we try to download a figure into a particular image type.
Merge pull request #2645 from loicseguin/show-source-link

Add option to show/hide the source link in plot_directive
plot_date: Set the default fmt to 'o'

Different to just plot() plot_date() has a default plot format string
which makes it necessary to *unset* the default one when drawing
multiple sequences of dates in a figure to get a working color cycling.
It also was not exactly clear that Axes.set_color_cycle was setting the
color cycle for every plot command except for plot_date ones.

It was of course possible to simply unset it after reading the
documentation but that's not the path of least suprise.

The default fmt of 'o' will keep the markers by default (which makes
sense for dates) but allows color cycling to happen.

This is related to issue #2148
Merge pull request #2641 from mineo/plot-date-fmt

plot_date: Set the default fmt to 'o'
Merge pull request #2648 from JamesMakela/master

Update backend_webagg.py
Fix #2636: Non-ascii characters coming from TeX are wrong
Merge pull request #2636 from mdboom/font/unicode-python3-pdf

"\usepackage[russian]{babel}" does not work in matplotlib 1.3.1
Use IPython's copy of ipython_console_highlighting if it is available.
Remove redundant colormaps from examples

`gist_yarg`, `gist_gray`, and `binary` are identical to `gray`, so they are "on a deprecation path", and `spectral` was renamed to `nipy_spectral` to avoid conflicts with `Spectral`

https://github.com/matplotlib/matplotlib/pull/889
DOC: Move spectral colormaps together

`Spectral` was missing, and `hsv` and `nipy_spectral` shouldn't be in the qualitative group, which are the 8 colormaps dumped here from ColorBrewer but that shouldn't really be here
Merge pull request #2659 from endolith/patch-3

DOC: Remove redundant colormaps from examples
Merge pull request #2515 from tacaswell/locatable_twin

overloaded `_make_twin_axes` on `LocateableAxesBase`