WIP: Engine Base Image and API

I've tweaked a few of the ansible playbooks or created new ones to make a striped down image with only what is needed for the engine API... The playbooks may be better organized as [ansible best practices](http://www.ansibleworks.com/docs/playbooks_best_practices.html) at some point, but this works.

The API is just a skeleton at the moment, but any comments are welcome!