Associate Element References (#1497)

During the planning phase of a project many diagrams and versions of diagrams are created. These diagrams often contain different copies of objects that turn out to be the same object (across different diagrams) after some revisions. If this connection is know in advance, the objects can be "drag & dropped" and a reference list can be accessed. If the connection is not known in advance, it is not possible (to my knowledge) to create this connection other than removing the object and restoring it from the other diagram (using drag & drop).

It would be nice to have a tool to associate these set of objects and from two different objects create references to a single object instead. (Possibly merging the properties and attributes of the objects.)