Flag an error if network is deleted which has ports attached to it

[Sukhdev Kapur]

During initialization of Arista driver make sure to clean its DB to get in sync with neutron DB. This ensures that Arista driver's DB and neutron's DB are in sync.

Also, when a network delete is issued to Arista driver, fail this command if there are ports attached to this network

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/309622
Committed: https://git.openstack.org/cgit/openstack/networking-arista/commit/?id=5252768cbe3d76aef2e6124424ec741077ffeb57
Submitter: Jenkins
Branch: master

commit 5252768cbe3d76aef2e6124424ec741077ffeb57
Author: Sukhdev Kapur <email address hidden>
Date: Fri Apr 22 16:26:31 2016 -0700

    Do not delete a network with ports attached to it

    If a network has ports attached to it, do not delete the network
    instead raise an exception so that user knows about this
    condition.

    Additionally, during initialization, when networks are deleted,
    remove all the ports associated with the network.

    Change-Id: Idb72305ac37dfe0c865fe09fbc5ab784d807906d
    Closes-bug: #1573207

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/liberty
Review: https://review.openstack.org/309646

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/kilo
Review: https://review.openstack.org/309651

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/309651
Committed: https://git.openstack.org/cgit/openstack/networking-arista/commit/?id=a55152054688310e9dc57156aa3a41ce21003930
Submitter: Jenkins
Branch: stable/kilo

commit a55152054688310e9dc57156aa3a41ce21003930
Author: Sukhdev Kapur <email address hidden>
Date: Fri Apr 22 22:19:20 2016 -0700

    Do not delete a network with ports attached to it

    If a network has ports attached to it, do not delete the network
    instead raise an exception so that user knows about this
    condition.

    Additionally, during initialization, when networks are deleted,
    remove all the ports associated with the network.

    This manual cherry picking becuase of split of repos in stable/kilo

    Closes-bug: #1573207
    cherry picked from Change-Id: Idb72305ac37dfe0c865fe09fbc5ab784d807906d

    Change-Id: I5c570fc6ad1cb0eb885a105213b253a222cd68a2

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/309646
Committed: https://git.openstack.org/cgit/openstack/networking-arista/commit/?id=67fad0aab65a56ef216179fa65f62add69c9394f
Submitter: Jenkins
Branch: stable/liberty

commit 67fad0aab65a56ef216179fa65f62add69c9394f
Author: Sukhdev Kapur <email address hidden>
Date: Fri Apr 22 16:26:31 2016 -0700

    Do not delete a network with ports attached to it

    If a network has ports attached to it, do not delete the network
    instead raise an exception so that user knows about this
    condition.

    Additionally, during initialization, when networks are deleted,
    remove all the ports associated with the network.

    Change-Id: Idb72305ac37dfe0c865fe09fbc5ab784d807906d
    Closes-bug: #1573207
    (cherry picked from commit 5252768cbe3d76aef2e6124424ec741077ffeb57)