MBS-5491: check for 'vs.' and 'feat.' in PossibleCollaborations report
MBS-5912: report for releases with cover art relationships
MBS-6012: when extracts get an empty string back from wikipedia, don't try to display them
MBS-4364: don't merge gender, country, type, date for special artists
MBS-4364: update tests to ensure VA doesn't get arbitrary attributes added to it by merges
MBS-4364: add database-level constraint
MBS-4364: also don't merge IPIs
Merge branch 'mbs-4364-special-artist-type-gender-country-etc' into beta

* mbs-4364-special-artist-type-gender-country-etc:
  MBS-4364: also don't merge IPIs
  MBS-4364: add database-level constraint
  MBS-4364: update tests to ensure VA doesn't get arbitrary attributes added to it by merges
  MBS-4364: don't merge gender, country, type, date for special artists
Merge branch 'mbs-6012' into beta

* mbs-6012:
  MBS-6012: when extracts get an empty string back from wikipedia, don't try to display them
Merge branch 'mbs-5912' into beta

* mbs-5912:
  MBS-5912: report for releases with cover art relationships
Merge branch 'mbs-5491' into beta

* mbs-5491:
  MBS-5491: check for 'vs.' and 'feat.' in PossibleCollaborations report