This introduces the same versioning scheme we use in Review Board and

other packages. Version information lives in reviewbotext/__init__.py,

and setup pulls that information in for the package.
To simplify setup.py, the explicitly-defined package data has been

removed, using a MANIFEST.in file instead. This is nicer in that we can

make use of rules like 'recursive-include', instead of having to list

files in each directory explicitly.

Built a package and inspected the resulting version and package contents.