additional nova service params, changes

Moved initialization to nova service class, as is done for passwords
changed nova_network to network_manager to match OpenStack terminology
added the other UI fields to the model
added dynamic param setting for network_manager to seeds -- other params
  are still needed there, pending further definition.
added neutron service

includes service model work, and seeds.rb data
FIXME: smart param values which evaluate to arrays aren't working yet
an erb/template string results in errors when foreman/puppet expects an array
Currently it's hacked to include content as a string in an array of length 1
but this obviously is broken in the case where the array has 2 entries.