mbs-6201: SQL for event collections

fixing some weird mess
mbs-6201: adding cardinality to relationships
mbs-6201: unfuck the tab name stuff
Merge branch 'schema-change-2014-q4' of https://bitbucket.org/metabrainz/musicbrainz-server into events-collections-sql

Conflicts:
	admin/sql/updates/schema-change/21.slave.sql
	upgrade.json
Merge remote-tracking branch 'reosarevok/events-collections-sql' into schema-change-2014-q4

* reosarevok/events-collections-sql:
  mbs-6201: unfuck the tab name stuff
  mbs-6201: adding cardinality to relationships
  mbs-6201: SQL for event collections