rbmotd and rbseverity now define their version information in a set of

functions and variables in their top-level packages.
setup.py has been updated to use these, and to also remove the

dependency information we don't want to require there (as it can mess up

an install if not running a new enough version of Review Board).
Classifiers have been added to help organize these packages on PyPI.
There's also a .beanbag-build.cfg for each, which are used to make it

easy to build and release these packages.

Built packages for both rbmotd and rbseverity. Also performed releases.