Fix Cisco nexus plugin failure for first VLAN on phy interface

[Dane LeBlanc]

With the Cisco nexus plugin, whenever an instance is created and this results in the configuration of the first VLAN on a Nexus switch interface, the Nexus switch rejects the configuration, and the instance creation fails.

A workaround is to pre-configure the switch interfaces with the following:
    switchport trunk allowed vlan none

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/29190

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/29190
Committed: http://github.com/openstack/quantum/commit/92ef293d02a7499850bc3becda413d6be22ae06c
Submitter: Jenkins
Branch: master

commit 92ef293d02a7499850bc3becda413d6be22ae06c
Author: Dane LeBlanc <email address hidden>
Date: Fri May 10 17:54:04 2013 -0400

    Fix Cisco nexus plugin failure for first VLAN on phy interface

    Fixes bug 1174852

    This fix changes the command being sent to the Nexus switch for
    enabling a VLAN on an interface such that the 'add' keyword is
    included only when there are prior VLANs already enabled on that
    interface.

    Change-Id: I466bcb839912b164b84be0e6721d87206c0e53eb

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/grizzly
Review: https://review.openstack.org/32416

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/grizzly
Review: https://review.openstack.org/32418

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/grizzly
Review: https://review.openstack.org/34950

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/34950
Committed: http://github.com/openstack/quantum/commit/678690e3cee62b49c15c69139fac3c332abd46db
Submitter: Jenkins
Branch: stable/grizzly

commit 678690e3cee62b49c15c69139fac3c332abd46db
Author: Dane LeBlanc <email address hidden>
Date: Fri Jun 28 16:19:02 2013 -0400

    Fix Cisco nexus plugin failure for first VLAN on phy interface

    Fixes bug 1174852

    This fix changes the command being sent to the Nexus switch for
    enabling a VLAN on an interface such that the 'add' keyword is
    included only when there are prior VLANs already enabled on that
    interface.

    (cherry picked from commit - 92ef293d02a7499850bc3becda413d6be22ae06c)

    Change-Id: I900e0cac9f88d38b5276a65bdfa7457aed466199