Switch to readily provisioned Vagrant box

This implements the agreed upon initial approach by manually creating a box via `vagrant package` as needed once in while and relying on the conceptually idempotent `install_dependancies` scripts to catch up any interim source changes, if need be.

I'm not convinced yet this will be more useful than as a proof of concept, insofar the lack of automation and resulting manual box URL management etc. yields usability issues for both producers and consumers of said box (for this reason I've also just commented out the original box spec, insofar it remains needed for updates of course).

So I guess the question is, it is worth to apply the approach for the time being, or upgrade to a much more versatile and easily automated Packer based solution right away?