Navigation toolbar redraw button

I might even suggest replacing the "pan" and "zoom"

    > buttons by just using left-click and right-click for the
    > drag. That way I can change tasks without mousing
    > around. Zoom-rectangle could even be middle-click.

This is the way VTK does it and it is great. All three mouse buttons
are used for pan, zoom and rotate. The only problem is for
application developers using matplotlib, who will probably want to
reserve some of the mouse buttons over figures for context menus or
measurement tools, etc... I have done both in my applications. Its
possible to do both via different toolbars, but there are only so many
hours in the day. I'll let it simmer.