Bud behind a CDN

[matthewmueller]

Bud applications should work nicely as an origin server behind a CDN. This seems to require:

• Settings the proper cache headers for the various types of content.
• asset_path helper function that's provided to the views (see Rails documentation for inspiration)

The types of assets that can be cached long-term are:

• Files in the public/ directory
• Controller-less views