Clean up the display of NIC assignment

The assignment table did not display the correct data in the correct
columns. This makes the display correct. Also changes the display of the
VIPs to use the tag instead of the auto-created MAC.
Merge pull request #361 from bcrochet/assign_display

Clean up the display of NIC assignment
Enable HA ceilometer

Adds support for HA Ceilometer to a deployment. Also adds a NoSQL
(Mongo) class to the HA Ceilometer service.