[wip] Combine production playbooks into a single playbook.

Rather than using three playbooks in a certain order to deploy production, staging and Jenkins, create a single entry point and use playbook and include variables to control the differences between them.
I try to only use quotes where they're actually necessary, just to minimize the syntax a little.

I might do a pass later and take out some of the JSON-style stuff in the nginx configuration later. :lipstick: