Simplification of stripping logic.

Hi Jon,

I'm a long-time gedit user, who recently switched to Emacs, but wants to switch back to gedit, but can't because Emacs has some killer features that I love. Anyway, your project intrigued me because this is a feature that I'd grown to rely on in Emacs.

I was a little bit put off by the verbosity of this plugin, however, so I attempted to simplify it, and this is what I ultimately came up with. It's still a far cry from [the Elisp implementation I wrote](http://paste.ubuntu.com/1269050/), but it's not a very fair comparison because `save-excursion` is provided by Emacs, where I had to write it from scratch in Python.