Plugins without quota extension fail to start due to missing quota table

[Akihiro Motoki]

As reported in bug 1236970, plugins without quota extensions fail to start due to missing table in the database.
This is the side effect of the recent commit: Quota DB driver has been recently enabled by default"
https://review.openstack.org/#/c/49993

If a plugin has no support of quota extensions, quota_driver should fallback to the config quota driver.
Otherwise we need to add quota extension support to all plugins.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/50608

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/50608
Committed: http://github.com/openstack/neutron/commit/46495f4995b6604cb249b688aaa249ef4e8b18ef
Submitter: Jenkins
Branch: master

commit 46495f4995b6604cb249b688aaa249ef4e8b18ef
Author: Akihiro MOTOKI <email address hidden>
Date: Wed Oct 9 19:50:35 2013 +0900

    Fallback to Quota Conf Driver if Quotas table is not defined

    commit de15e0b9c5 enabled Quota DB driver default considering
    production environments, but it breaks plugins without per-tenant
    quota extension. In these plugin quotas tables is not loaded.

    This commit fallbacks to ConfDriver if Quota model is not loaded by
    checking neutron.db.quota_db which defines Quota model is imported.

    Change-Id: Idaaaa9810598cfd3e5ce70020f498643b4819d16
    Closes-Bug: #1236993

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: milestone-proposed
Review: https://review.openstack.org/51321

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/51321
Committed: http://github.com/openstack/neutron/commit/438b2ebfcd879571504359881f3881f60179e7f1
Submitter: Jenkins
Branch: milestone-proposed

commit 438b2ebfcd879571504359881f3881f60179e7f1
Author: Akihiro MOTOKI <email address hidden>
Date: Wed Oct 9 19:50:35 2013 +0900

    Fallback to Quota Conf Driver if Quotas table is not defined

    commit de15e0b9c5 enabled Quota DB driver default considering
    production environments, but it breaks plugins without per-tenant
    quota extension. In these plugin quotas tables is not loaded.

    This commit fallbacks to ConfDriver if Quota model is not loaded by
    checking neutron.db.quota_db which defines Quota model is imported.

    Change-Id: Idaaaa9810598cfd3e5ce70020f498643b4819d16
    Closes-Bug: #1236993
    (cherry picked from commit 46495f4995b6604cb249b688aaa249ef4e8b18ef)