UI tweaks primarily to reduce columns in queue list and clean up queue details:

* Rename "parameters" here to "features" (since we meant "arguments and a bit
  more", not the same as actual parameters!)

* Show the policy in the listing in a way that makes it look like a feature,
  lose one column

* Show the queue's exclusive owner, if there is one, in a way that makes it
  look like a feature

* Hide 'rabbit@' in node names since almost all nodes will be called
  rabbit@something. Still show the node name if it is anything other than
  rabbit.

* Show "implicit args" first, since durable will be popular

* Only show exclusive owner on the details page if it exists. And if it does,
  don't show slaves since they can't exist.

* adjust exchanges to match