Enable scraping / updating album art from Fanart.tv

[smidley]

A cool feature would be to enable scraping artwork (primarily albumart) from the fanart.tv website. http://fanart.tv/

This could be used to replace lower resolution artwork that you currently have, with high quality versions. It would also be nice if subsonic would be able to take these art files and embed them into the MP3 files ID3 tags.