[Python-mode] evil underscore as word

[skip@pobox.com]

    Barry> From my python-mode-hook:

    Barry>   (define-key py-mode-map [(meta f)] 'py-forward-into-nomenclature)
    Barry>   (define-key py-mode-map [(meta b)] 'py-backward-into-nomenclature))

So maybe we can solve this in python-mode.el.  Leave the syntax category for
"_" alone and add (yet another) flag that rebinds M-f and M-b accordingly.

Skip