HTTP last-modified header on album art

[justindhill]

Even though this value will never be changing, it's crucial to have this header, because it signals to browsers that the content is cacheable. Definitely want to cache album art in browsers.

[mdlayher]

I've implemented a patch for this, but last modified times are still screwy on my system. I keep getting ridiculous output timestamps like 634881726210000000. Maybe because I'm using XFS? I'll keep looking.

Patch coming up in a sec.

[einsteinx2]

Merged.