BigSwitch plugin: Unnecessarily deletes ports from backend on network delete.

[Kevin Benton]

The Big Switch plugin unnecessarily deletes individual ports from the controller when a network is being deleted. This isn't needed because the controller will automatically clean up the ports when their parent network is deleted.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/81952

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/81952
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=083324df06828e1b8fb97220b7415c2a28ee16c4
Submitter: Jenkins
Branch: master

commit 083324df06828e1b8fb97220b7415c2a28ee16c4
Author: Kevin Benton <email address hidden>
Date: Thu Mar 20 06:48:45 2014 -0700

    Big Switch Plugin: No REST port delete on net del

    Moves the REST call for port deletion out of the
    _delete_port method into the delete_port method
    so it doesn't get called during a delete_network
    operation. The backend controller automatically
    removes ports that are a member of a network when
    it's deleted.

    Closes-Bug: #1295438
    Change-Id: Ic09eb722f8e9bd3ce298dee90d8415cda1a1aa7a