Discogs has changed their URLs for artists and labels to include IDs (finally!), e.g. http://www.discogs.com/artist/3554355-Levantis-2 and http://www.discogs.com/label/142328-The-Trilogy-Tapes

For consistency with releases and masters, we probably want to detect thoses and turn them into http://www.discogs.com/artist/3554355 and http://www.discogs.com/label/142328