OVS agent deletes tags when connection lost with DB

Fix proposed to branch: master
Review: https://review.openstack.org/6744

Reviewed: https://review.openstack.org/6744
Committed: http://github.com/openstack/quantum/commit/be45b704ac6fc39e9f934f886403a622c30803cb
Submitter: Jenkins
Branch: master

commit be45b704ac6fc39e9f934f886403a622c30803cb
Author: Gary Kotton <email address hidden>
Date: Tue Apr 24 02:02:03 2012 -0400

    blueprint agent-db-ha
    bug 985470
    bug 985646

    The fixes enable the OVS and linuxbridge agenets to "keep alive" when the host running the server/plugin is down.

    Fixes after comments. Better logging

    Fixes after comments - added reconnect interval + cleanup

    Fixes after comments - simplify code + ovs intervals moved to configuration file

    Fixes after comments - move int conversion to configuration

    Fixes after comments - if one of the polling interval or reconnect interval are not
    defined in the relevant ini files then a default value is used.

    Fixes after comments and merges with HACKING.rst fixes

    Fixes after port binding comments

    Fixes after comments from gongysh

    Fixes after comments - align comments in agent ini files

    Fixes - revert some code

    Change-Id: I9194f142478b130e8ef198b019539357a9916d7f