Extend Reference to all entities

[philsward]

From what I can tell, the ultimate goal is to extend the Reference module to work with all entities, however it currently does not work with entities that are not part of core.

This piece should be coded such that any entity can be referenced without having to explicitly be coded either by the Reference module or each respective module that declares entities. I think it is too much overhead for both the reference piece and respective contrib modules to code that they are compatible with Reference and instead, Reference should simply check to see "Is it an entity", if yes "Allow it to be Referenced".