make generic, expand README

Makes the cookbook work outside vagrant (tested on both a bare-metal and ec2 ubuntu 12.04 instance)

Actually the one thing I haven't been able to do is test it in a Vagrant - my setup is currently all busted, and I have to run for now. If you could give it a whirl in a Vagrant and make sure it still works, that'd be awesome. Otherwise, I'll do it when I get back and figure out what's wrong with mine. Thanks!

[fixes #1]