Don't reload the artist information if we've got it saved in the bundle (ie orientation change)

It seems like there's some funny business with serializing Maps with Gson so for now the Releases don't get serialized. I'll look into this more and hopefully we can save everything, as rebuilding the releases could be pretty costly for artists with tons of them
Migrate Torrent group activities to use the editions stuff in develop

This fixes us accidently showing different media releases of the original release as the same release.