Fixed bad quiver transforms.
Fixed failing test on travis.
Attempt at updating the pickle image test.
Merge pull request #2444 from pelson/quiver_trans

Fixed bad vector transforms.
Fix how figure id is passed to browser to support Tornado 3.2
Merge pull request #2849 from mdboom/webagg/tornado-escape-fix

WebAgg issue - Uncaught SyntaxError: Unexpected token &
Work around subprocess.CalledProcessError on Google App Engine

Set subprocess.CalledProcessError to None on restrictive environments
like Google App Engine because the exception cannot be raised and there
is no need to catch it. Fixes #1825 which broke after #1857.
Merge pull request #2860 from daradib/subprocess-google-app-engine

Fix subprocess.CalledProcessError on Google App Engine
Merge remote-tracking branch 'upstream/v1.3.x'
 - quiver had two functions added next to each other, easy merge
 - all_figures.html had non-trivial due to prior refactor on master
 - changes to axes.py needed to be split between _axes.py and _base.py

Conflicts:
	lib/matplotlib/axes/_axes.py
	lib/matplotlib/backends/web_backend/all_figures.html
	lib/matplotlib/quiver.py