Fixed bad quiver transforms.
Fixed failing test on travis.
Attempt at updating the pickle image test.
Fix IPython detection.  Fix encoding error on Python 3
Remove _in_ipython
Merge pull request #2444 from pelson/quiver_trans

Fixed bad vector transforms.
Fix positional/kwarg handling of the Z argument
Fix how figure id is passed to browser to support Tornado 3.2
Require minimum six 1.5
counterclock parameter for pie
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.
GTK3 backend: implemented FigureCanvasBase.resize_event()
Merge pull request #2867 from timovwb/master

GTK3 backend: implemented FigureCanvasBase.resize_event()
Fix for issue #2872. In case of missing values (e.g., zeros when using a logarithmic scale), draw_path_collection may get offsets containing NaN's. In that case, using CGContextTranslateCTM once with translation and once with -translation will not restore the original CTM. This bugfix adds a check for NaN/inf.
Merge pull request #2865 from vmarkovtsev/master

WebAgg: raise WebAggApplication.started flag before blocking
Merge pull request #2860 from daradib/subprocess-google-app-engine

Fix subprocess.CalledProcessError on Google App Engine
Merge pull request #2852 from mdboom/six-minimum-version

AttributeError: 'module' object has no attribute 'next'
Merge pull request #2851 from WeatherGod/mplot3d/fixtri

Fix positional/kwarg handling of the Z argument
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