Clarify documentation for FuncAnimation
more FuncAnimation documentation tweaking
Merge pull request #1890 from pelson/travis_inkscape

Restored inkscape installing on travis-ci.
Fix #1894: Composite images do not have a transparent background
Merge pull request #1887 from alito/master

Clarify documentation for FuncAnimation
Merge pull request #1894 from mdboom/image/composite_background

Fixes background coloring of multiple images on the same axes.
Merge remote-tracking branch 'upstream/v1.2.x'
Fixed hatch patch clipping and did some minor refactoring of
_backend_agg.cpp.