MBS-5861: SQL for work attributes
work attribute updates

rename attribute_name to attribute_type
add ability for attributes to be free text as well as from list
remove edit_work_attribute table (not needed)
Add tables to dump, import. Add upgrade scripts
Merge branch 'mbs-5861' of https://bitbucket.org/alastairp/musicbrainz-server into mbs-5861
Making the last needed changes to this so it can ship
Merge branch 'schema-changes-2013-05-15' of https://bitbucket.org/metabrainz/musicbrainz-server into mbs-5861

Conflicts:
	admin/sql/CreateIndexes.sql
	admin/sql/DropIndexes.sql
	upgrade.sh
Updating table name in two files I missed (oops)
Adding primary key creation stuff
Fixing wrong table name on triggers
Adding suggested index work_attribute_idx_work
Add trigger
Extending the test
Fix a couple problems with the trigger + test
expanded func/trigger name, added to update script
Merge remote-tracking branch 'reosarevok/mbs-5861' into schema-changes-2013-05-15

* reosarevok/mbs-5861:
  expanded func/trigger name, added to update script
  Fix a couple problems with the trigger + test
  Extending the test
  Add trigger
  Adding suggested index work_attribute_idx_work
  Fixing wrong table name on triggers
  Adding primary key creation stuff
  Updating table name in two files I missed (oops)
  Making the last needed changes to this so it can ship
  Add tables to dump, import. Add upgrade scripts
  work attribute updates
  MBS-5861: SQL for work attributes