Static file mounting

This begins the adventure of both:

* Sticking nginx in a container
* Mounting static assets from the userland container to the nginx container

This also tosses the `static.tar` legacy file.
Even if we hash-fingerprint them, we're still serving a specific set from nginx rather than what any given container is necessarily running.

If we wanted to though, we could finish up the piece from tmpnb's tornado app that handles static asset serving. Right now it only serves `static.tar` when it could serve static for each path (making sure to key on image id).