Stacks that have been soft deleted remain locked

[Clint Byrum]

It is not at all clear why, but in the TripleO CD cloud, these stacks are not able to be purged because they still have records in the lock table:
mysql> select * from stack s inner join stack_lock sl on sl.stack_id = s.id where s.deleted_at is not null limit 1\G
              id: 10b1acc2-cb8c-43e9-90e3-9cffa471d284
      created_at: 2013-12-20 10:40:04
      updated_at: 2013-12-20 17:29:17
            name: overcloud
 raw_template_id: 1191
   user_creds_id: 1189
        username: admin
        owner_id: NULL
          status: COMPLETE
   status_reason: Stack delete completed successfully
      parameters: {XXX}
         timeout: 60
          tenant: 4956c533154c476799c688eda7ed65ab
disable_rollback: 1
          action: DELETE
      deleted_at: 2013-12-20 17:29:17
        stack_id: 10b1acc2-cb8c-43e9-90e3-9cffa471d284
      created_at: 2013-12-20 17:28:43
      updated_at: NULL
       engine_id: b9c17fed-f2c1-4851-b6cb-424063d69b50

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/71390

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/71390
Committed: https://git.openstack.org/cgit/openstack/heat/commit/?id=cafe45ecc5b80e4df34acc44ed2d38cd1658a018
Submitter: Jenkins
Branch: master

commit cafe45ecc5b80e4df34acc44ed2d38cd1658a018
Author: Jason Dunsmore <email address hidden>
Date: Wed Feb 5 14:45:41 2014 -0600

    Ensure stack lock is released after stack-delete

    Previously, stack locks would not be released after a stack-delete
    because the stack ID was being passed to db_api.stack_lock_release() as
    None. To resolve this, pass the stack ID to the greenthread-linked
    release function while it still exists.

    Change-Id: I260c4c5512bd2069f134e9d6ac6ea07565e443b0
    Closes-Bug: #1276336