Fixed bad quiver transforms.
Fixed failing test on travis.
Attempt at updating the pickle image test.
WebAgg: extracted figure_div style into css and changed layout

Set #figure-div display style to inline-block to use free space on the page
more effectively. See http://www.vanseodesign.com/blog/demo/inline-block/.
Additionally, set margin to 10px around every figure, so padding-bottom
becomes unnecessary.
WebAgg: reuse already running Tornado ioloop

    If a Tornado ioloop is already running before WebAggApplication.start() is called,
    it should be re-used instead of trying to start it again. This allows one to
    use WebAgg in his/her external Tornado application.
Fix IPython detection.  Fix encoding error on Python 3
Remove _in_ipython
Fix bug in horizontal step histograms
Merge pull request #2846 from neggert/hist_step_horiz_bugfix

Fix bug in horizontal step histograms (#2830)
added demonstration of separate horizontal/vertical axes padding
implemented separate horizontal/vertical axes padding
improved coding style, removed unused imports
Reverted import removal, reformatted an if-else
Removed lines that were commented out previously
Described changes done in pull request #2731
PEP8 indentation fixes
Merge pull request #2731 from matejak/2d-padding

2d padding
Merge remote-tracking branch 'upstream/v1.3.x'
Merge pull request #2444 from pelson/quiver_trans

Fixed bad vector transforms.
Fix positional/kwarg handling of the Z argument