matplotlib Code

make sure griddata issues verbose report only the first time it is called.

added some additional comments to axes to clarify the patch/frame relationship

fixed symlog locator transform bug sf id 2029141

make sure axes.frame (not axes.AxesPatch) used to define properties
of map boundary line.

restored axes frame, made patch edge invisible

mpl_toolkits._natgrid now exists

Render Wx backends only when necessary

Fix wx event loops

Fix a doc typo.

Fix a couple of docstring typos.