Updated the macosx backed figure manager show function to bring the
figure to the front upon execution.
New rcParams to set pyplot.suptitle() defaults

Two new rcParams are introduced:

- figure.titlesize (xx-large)
- figure.titleweight (normal)

Allow to set the pyplot.suptitle() default font size and weight.
Add a "whats_new" entry for the new figure.title* rcParams.
Merge pull request #3762 from vmarkovtsev/patch-1

MNT : WebAgg: flush stdout after printing, redirect "stopped" message to stder
Fix Sphinx warning in widgets

And improve the rendering of the docstring somewhat.
fixed axvline description of ymin/ymax args. Little edit in axhline doc
pyplot updated
Merge pull request #3788 from jenshnielsen/widget_docs_fix

Fix Sphinx warning in widgets
boilerplate.py run against master (v1.5.x)
PEP8 error fixed
Merge pull request #3083 from wavexx/suptitle

ENH : New rcParams to set pyplot.suptitle() defaults
Merge pull request #3698 from montefra/axvline_doc

DOC : fixed axvline description of ymin/ymax args. Little edit in axhline doc
Fix for #3789, segfault in _tri
Fix #3790. Correctly scale quadmesh linewidth to dpi in Agg backend.
Merge pull request #3793 from mdboom/quadmesh_linewidth

Correctly scale quadmesh linewidth to dpi
Merge pull request #3797 from ianthomas23/3789_segfault

Fix for #3789, segfault in _tri
Merge remote-tracking branch 'upstream/v1.4.x'

Conflicts:
	src/_backend_agg.cpp
Update test image for slight difference in calculation between 1.4.x and master
BLD: Modified mocksip to allow for building the docs without qt being
installed
STY: pep8 fixes