Enable EDP on private neutron networks

The changes here enable the execution of EDP jobs via private net
IPs rather than public IPs.  Some key points:

- The changes still support the use of public IPs (clusters
leveraging public IPs were tested as well)
- Information required to establish neutron-based connections
(HTTP and SSH) are stored as part of the job configuration in order
to support the periodic job execution lookup tasks (which do not
have the context to retrieve this informatoin via the neutron client)

Fixes: bug #1261541

Change-Id: I48b49882e910886bf9407b82feab7eb27272fa79
Merge "Enable EDP on private neutron networks"