BZ #1094444 - Add support for neutron-nova notifications on port changes

https://bugzilla.redhat.com/show_bug.cgi?id=1094444

Recent versions of neutron added the ability for neutron to notify nova
of port changes. This implements those changes for both standalone
and HA controller. The settings must be done on the controller node.

This also adds the neutron::server to standalone neutron node.
Merge pull request #216 from bcrochet/neutron-notifications

BZ #1094444 - Add support for neutron-nova notifications on port changes