BZ#1149777: Add host id to neutron.conf

https://bugzilla.redhat.com/show_bug.cgi?id=1149777

In order for services to fail over properly, a host id must be added to
the DEFAULT section of neutron.conf. This must match on all nodes
involved in the failover.
Merge pull request #387 from bcrochet/bz/1149777

BZ#1149777: Add host id to neutron.conf