[MGM] Provide a more useful log message when novaclient fails

Change-Id: I41cf2a2cc849a3dde898ec2277d1c3b57d331435
[MGM] Support nova_net_id option when there are n+ Neutron networks

Change-Id: I99b6b9b8ff386ca77ce24e23ff1fa07b96546472
Doc improvements

* Add install section
* Move getting-started into install/development
* Production reference architecture with diagram / notes.
* Production installation guide using PPA for now.

Change-Id: Id4317eb5295d1ce612e43d0ef4ca24cce63f46bf