Make pyplot.bar color kwarg less ambiguous
Merge pull request #2308 from dmcdougall/v1.2.x

Make pyplot.bar color kwarg less ambiguous
Added check in autoscale_None for completely masked pcolor plots.
Python3 handling of None > None.
Merge pull request #2336 from pelson/completely_masked

Added check in autoscale_None for completely masked pcolor plots.