matplotlib Code

Remove empty "else" clause.

Remove unnecessary declaration.

Support reading low-bit depth (< 8) PNG images. Add PNG test suite to make sure we're supporting the basic kinds of PNG files available.

defer import of netcdf module

Make shared axes work better with constrained aspect ratio.
This is restricted to the case of adjustable=datalim, and is
experimental.

Support autoscaling with shared axes

Update movie_demo.py to work with current mpl.

Fix math expression.

Fix duplicate aliases.

Fix collections property list.