Merged initial Sphinx documentation structure.

Merged initial Sphinx documentation structure.

There's still a long way to go in this direction, but the basic
framework is now in place.  Toss in numpydoc-style docstrings
  http://projects.scipy.org/numpy/wiki/CodingStyleGuidelines
when you have time, and things will gradually improve over time.

I also punted our user ID creation/parsing in libbe.ui.util.user to
the email module.  This way IDs are handled in an RFC-compliant way
(less suprising for users) and by someone else (less work for us :).