Add an API flag for force delete from storage

[Vinod Mangalpally]

Add an API flag for force delete of zones from storage. Recordsets would not have this feature. By default this is restricted by policy to admins.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/148779

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/148779
Committed: https://git.openstack.org/cgit/openstack/designate/commit/?id=c3afc3f4bb2f1d1c4bf8a46d11ee6c506814c35c
Submitter: Jenkins
Branch: master

commit c3afc3f4bb2f1d1c4bf8a46d11ee6c506814c35c
Author: Vinod Mangalpally <email address hidden>
Date: Wed Jan 28 13:39:31 2015 -0600

    Add a new API for abandoning a zone from storage

    Add a new API for abandoning of zones from storage.
    The new API would be v2/zones/<zone_id>/tasks/abandon
    Only POST would be allowed on this API.
    This just removes it from storage and does not take
    any action on the backends.
    Recordsets would not have this feature. By default this is
    restricted by policy to admins.

    Deleting a zone returns 202. Abandoning returns 204.
    Zone now displays action too.

    Change-Id: I213b567d1b609670b7c659f6e9780bdac240c89b
    Closes-Bug: 1413024