New option url_prefix

[ozten]

url_prefix - A url prefix to append to links generated in cachify_js and cachify_css.

Examples:

• "http://cdn.example.com/media/"
• "cachify"

Using url_prefix, one could support dark launches, since all assets are revisioned with hashes and the CDN network would service your request.

Using a string instead of a CDN url ("cachify") would make the middleware more efficient when determining if an inbound request is a cachify request that should have it's url re-written.

[ozten]

Mostly fixed in

https://github.com/mozilla/connect-cachify/commit/fe8df0c486071d304def714bf61a3a79f3ed0dc3

https://github.com/mozilla/connect-cachify/blob/master/docs/API.md

Adding a last patch so that urls can be used in the prefix option.

[ozten]

Okay, I think that does it. Pushed version 0.0.4.