MBS-3971: Display recording relationships at the bottom of the release page
Add back "has no relationships" notice
Merge branch 'beta' of git://github.com/metabrainz/musicbrainz-server into mbs-3971
Always show medium prefix if there are *any* dup track numbers
separate var statements
refactor relationship grouping code a bit

 * move main logic to Entity::Release
 * move formatted_date to Entity::Link
 * don't use "each"
 * wrap a few lines to 80 cols
Merge pull request #68 from mwiencek/mbs-3971

MBS-3971, MBS-3810: Group relationships underneath tracks