Also py3fy category.py.

Only exception is axes_grid, whose removal should be accompanied by an
update to the docs.

…idspec or subplotspec

Simplify setupext by using globs.

so don't rely on the 3rd party version.

Also replace py.test by pytest in the docs (recommended since pytest
3.0, https://docs.pytest.org/en/latest/changelog.html#id281; we require
pytest>=3.1 anyways).

Also delete tox.ini which is clearly outdated.

Add a link from the examples to the user's guide.

Clarify that the weakref behavior only affects *methods* used as
callbacks, not free functions.

…strainedlayout

FIX/ENH CL: Allow single parent colorbar w/ gridspec layout

Minor fixes to event handling docs.

Currently, Matplotlib reuses axes when add_axes() is called a second
time with the same arguments.  This behavior is deprecated since 2.1.

However we forgot to deprecate the same behavior in gca(), so we can't
remove that behavior yet.

Also cleanup docstrings of Stack class.  Also,
process_projection_requirements cannot modify the outer kwargs (because
`**kwargs` is always a copy), so remove the incorrect note regarding the
need for copies.

Improve Figure docstrings

…stimestamp

ENH: check `.values` in more places

…nedlayout

PRF: Speed up constrained layout

Matplotlib.nib was used by the old cocoaagg backend (ef8e81e) which has
been deleted a while ago.

This is now consistent with the documentation:
https://matplotlib.org/users/event_handling.html

figure_enter_event uses now LocationEvent instead of Event. Fix issue matplotlib#9812.

Delete deprecated backends

Anything (approximately) starting with two underscores, or an underscore
and a capital letter is reserved in the C++ standard.

Python 3 always uses the new buffer protocol.

It's still not closed, but at least we can reference it later.

Remove Python 2 code from C extensions

More figure-related doc updates

Py3fy font_manager.

Some py3fication for matplotlib/__init__, setupext.

Fixes matplotlib#10501.  python3 support and pep8 in jpl_units