* Config doc: http://wiki.openstack.org/QuantumDevstackOvsXcp
* The Open vSwitch agent needs to be deployed on domU but
interact with a dom0 bridge.
* Add a root wrapper and associated XenAPI plugin to allow the
agent to execute networking commands against dom0 from domU.
* Update ovs_lib mac address discovery to use ip_lib to
ensure that discovery works even for bridges not local to
the agent (i.e. dom0 bridges). A bridge configured with
a dom0 root wrapper will execute ip link on dom0.
* Update ip_lib to use a root helper by default to ensure that
the 'ip' command will execute on dom0.
* Remove obselete rpm spec and installer for dom0 agent.
* Credit where credit is due - the XenAPI plugin and its
packaging were largely copied from nova.
* Supports blueprint xenapi-ovs
Change-Id: I7795446ee1267712c896f5cb3401f84fb1763ce7
7ff0c53564