slight update to scatter
Removed deprecated float-as-gray
Replace Ellipse.verts by Ellipse.get_verts()
Fixed rotation of ellipses in pdf backend.
changed the link for setuptools in the docstring.
Allow polar to be used interactively.
Tweaked matshow, documentation; set_bounds method for TickHelper mixin
Fixed matshow and spy tick locations, labels
remove unused import
added 'srs' instance variable.
