Adding code to return details for a specific node (by hardware_id value) from the list of all available nodes
Cleanup of the previous commit (with these changes, now correctly handles
where we are getting a matching node by Hardware ID but no matching node
was found; also includes updates a few variable names and additional comments
to make the code easier to follow)
Adds in the ability to retrieve an active_model based on the hardware_id of
the node that was bound to that active_model instance (also cleans up a few
issues with the previous commit, which added similar functionality to the
node slice)
Fixes issue where the new search by hardware_id and old retrieve by Hanlon UUID
returned different results in the RESTful API (the former returned an unexpanded
object while the latter returned an expanded object). This commit makes both act
the same way that the retrieve by Hanlon UUID always worked (returning the
expanded object, not just a reference via URI to it).
Merge pull request #178 from tjmcs/tb/find-match-by-hardware-id

Fixes #176 (Add ability to search for node/active_model via hardware_id)