Feature/fs2 backend stability rebase2

This PR is for the end-of-October mid-development release of the FS2 backend.  I caught a cold right before traveling to Ricon, so disease + jetlag made my first rebasing effort a mess of epic proportions.  A squash + rebase worked *much* better.

The commits to fix EUnit bugs also contain some real bugfixes wrt FS2 fold_objects.  Riak KV's handoff appears to be fully functioning again, yay.

See both of the edited README* files for installation instructions.  No Chef/Puppet thingies have been edited, sorry!