Added some function arguments to the documentation for FuncAnimation
Fix mpl_toolkits hyperlinks
Fix hyperlinks to pylab_examples
Fix auto-closing in PolyCollection
Add test png
Merge pull request #3239 from mdboom/polycollection-closed

Fix auto-closing in PolyCollection
Remove dregs of nxutils
Fixed backend workflow.
Merge pull request #3004 from mdboom/docs-nxutils

FAQ and unit/ still refers to nxutils
Merge pull request #3246 from dmcdougall/fix-doc-links

Fix some hyperlinks in the documentation

Edits only in rst files
Merge pull request #3243 from pelson/nbagg_proper

Fixed backend workflow.
Merge pull request #3217 from JulianCienfuegos/master

Added some function arguments to the documentation for FuncAnimation
Rewrite checks to use communicate.

This ensures that file handles are cloesed
Silence some more cloesed file warnings
Ensure that file is closed in texmanager
Remove leftover debug
Correct stdout in dvipng_hack