Kill the placeholder plugin.
Remove false comments
MBS-6230: ISE removing deprecated relationship
Only change the credit if it matches the old artist name
Merge branch 'beta' of bitbucket.org:metabrainz/musicbrainz-server into mbs-6230

Conflicts:
	lib/MusicBrainz/Server/Entity/LinkType.pm
Merge branch 'beta' of bitbucket.org:metabrainz/musicbrainz-server into kill-placeholders
Merge remote-tracking branch 'bitmap-bitbucket/mbs-6230' into beta

* bitmap-bitbucket/mbs-6230:
  MBS-6230: ISE removing deprecated relationship
Merge remote-tracking branch 'bitmap-bitbucket/kill-placeholders' into beta

* bitmap-bitbucket/kill-placeholders:
  Only change the credit if it matches the old artist name
  Remove false comments
  Kill the placeholder plugin.