Cache things in vagrant base image.
+x
Update main Vagrantfile with version.
Reorder dependencies in base Vagrantfile and rpm spec.

Making them match the order of `setup.py` makes it easier to verify that they are
complete.
Add some more [dev] dependencies to the image.
Address review comments.
Shorter line.
Add some hints about testing locally.
Remove unbalanced ``.
Merge pull request #226 from ClusterHQ/vagrant-precache-225

vagrant: Precache docker images, python packages and zfs

Fixes #225.