Reprogram flows when ovs-vswitchd restarts

[OpenStack Infra]

https://review.openstack.org/95060
commit 8e9f00a19dab98e5cfc7ca32beb9f17ebb5bc1bb
Author: Kyle Mestery <email address hidden>
Date: Fri May 16 04:21:32 2014 +0000

    Reprogram flows when ovs-vswitchd restarts

    When OVS is restarted, by default it will not reprogram flows which were
    programmed. For the case of the OVS agent, this means a restart will cause
    all traffic to be switched using the NORMAL action. This is undesirable for
    a number of reasons, including obvious security reasons.

    This change provides a way for the agent to check if a restart of ovs-vswitchd
    has happened in the main agent loop. If a restart of ovs-vswitchd is detected,
    the agent will run through the setup of the bridges on the host and reprogram
    flows for all the ports connected.

    DocImpact
    This changes adds a new table (table 23) to the integration bridge, with a
    single 'drop' flow. This is used to monitor OVS restarts and to reprogram
    flows from the agent.

    Change-Id: If9e07465c43115838de23e12a4e0087c9218cea2
    Closes-Bug: #1290486