initial stab at packaging using ship_it

So this is not yet ready to merge.  The good news is that I'm able to make an RPM with this changeset which seems to install properly.  The bad news is that now that we've changed Sideboard to use a single virtualenv, we are no longer able to bundle plugin Python dependencies with those plugins as easily :/

So basically, we need to be able to have packages somehow insert their dependencies into Sideboard's virtualenv on install.  We do NOT want to pull down from the internet when we do this.  Perhaps the solution is to include the packages and then do the equivalent of ``python setup.py install`` on each of them to make sure they're installed, but I'll need to give that some thought.
I went ahead and just included ``sh`` both because it's super-awesome and because we make use of it in our plugin ``fabfile.py`` for packaging.  Not that we really need to, but everyone should use ``sh`` so I'm happy to include this just to evangelize this.