Support for first-class data-only containers #56
Description
This is currently a bit rubbish; data only containers are started with a cluster, and then show up as being stopped on a decking status call. We should build in some extra logic (either automatic or part of config) so we can treat them separately and not include them in these commands, or at least render them differently so it's clear they don't need to be running as part of a cluster.
Still need to apply to a decking create though.