Python 3 fixes to Debian lsb package

[Jeff Licquia <licquia@debian.org>]

Did some testing of the lsb package on Python 3, and pushed a bunch of
changes to master.  As far as I can tell, the changes work on Python 2
as well (the tests don't fail, at least).

(And I screwed up my identity; didn't set it in my wheezy VM, so the
commit message got rejected.  Oh, well.)