Revisit Reference factory methods

[prdoyle]

Now that we have buildReferences, there's not much need to have a plethora of Reference factory methods. We should revisit these and trim them down to the most useful subset.

[prdoyle]

Perhaps buildReferences could be enhanced so it can accept a prefix path that it appends to. Then the then methods would never need to be called directly, even in highly generalized low-level framework code like MaintenanceEndpoints, and we could strip them down to the bare minimum required by buildReferences because they don't need to be handy to call anymore.