Implement references #9
Description
Depends on: #1
Proposal draft here. Likely this will remain a Draft until the syntax is ready to be implemented, but I don't mind implementing the base system for now.
References heavily influence the link system which will be implemented in #3
Otherwise, this issue covers implementing control of cloning and how a reference group stores data while dealing with cycles. This should also implement all the special references and, if possible, reserve /w*back/.