[engineer] neutron open-vswitch need to stop, and need to start l2_proxy.

[nash.xiejun]

1. Need to stop ' neutron-plugin-openvswitch-agent' by commands "# service neutron-plugin-openvswitch-agent stop"
    # mv /etc/init/neutron-plugin-openvswitch-agent.conf /root/openstack_bak/init/

2. Need to add following to rc.local to start l2_proxy.
vi /etc/rc.local
{ ps -eaf | grep l2_proxy.py | awk -F " " '{print $2}' | while read i; do kill -9 $i 2>/dev/null; done } || echo ignore error...

nohup /usr/bin/python /usr/lib/python2.7/dist-packages/neutron/plugins/l2_proxy/agent/l2_proxy.py --log-file /var/log/neutron/l2_proxy.log --config-file /etc/neutron/neutron.conf --config-file /etc/neutron/plugins/ml2/ml2_conf.ini >/dev/null 2>&1 &