Consider setting header: cache-control: no-cache

Just now when I decided to try Webamp's new Milkdrop feature (which is *amazing*), I had some trouble finding it. Wasn't until I refreshed the page that I realized I was seeing an older version.

It's strange, because I see `cache-control: public, max-age=0, must-revalidate` in the list of headers sent from Webamp and I thought that would be enough. Maybe it must be set to `Cache-Control: no-cache` to force the client to always check whether there is a new version.

Reproduce the stale-version behavior and inspect the response headers currently sent by Webamp, especially `cache-control: public, max-age=0, must-revalidate`. Compare the behavior with `Cache-Control: no-cache`; done means the browser checks for and receives a new version without requiring a manual refresh.

Written by the indexing model from the issue text.