Add BitBalloon deploy option

This adds BitBalloon as a deploy option.

BitBalloon is a static hosting service. Here's a few of the things BitBalloon does:

* Atomic deploys (with versions and easy rollback)
* CDN integration (with content addressable URLs, perfect cache-headers and instant cache invalidation)
* Easily setup staging/production sites
* Pretty URLs
* Supports redirects and rewrites
* HTML Forms work (contact forms, etc, automatically works)
* HTTPS (coming to custom domains very soon)