I had some difficulty setting up and maintaining my own gitian build
system. So in the time-honored tradition of scratching my own itch, I
recorded the necessary steps into a makefile so that doing a gitian build
is a simple as "cd contrib/vagrant && make", on any platform provided that
you have the necessary dependencies installed.

I hope that others find this useful. I have submitted these scripts as
pull-request #1597 on github.

Cheers,
Mark Friedenbach