Did some stuff with artist credit lookups.

It was a while ago, so not sure if it's stable or correct.
AJAX loading circle.
Merge branch 'master' of github.com:LordSputnik/waveplot-server into dev
Latest partials updates (from Pi).
Slight changes to MusicBrainz lookups to allow all releases to be cached.
Fixed cross-domain for extreme_dr(). Also tested, so merging to master.