Add support for non-referenced actors.

[jimsynz]

It's cool how you can say reference_source? false however if you happen to be adding the paper trail extension to your actor resource you need to also not generate the reference for the belongs_to_actor relationship.

[zachdaniel]

🤔 I'm not sure that makes sense. You could have an admin user editing a user other than themselves. The references_source? relationship points at the user being edited, the belongs_to_actor points to the actor doing the editing.

[jimsynz]

What if I change my own password and then try and delete my account?

[zachdaniel]

I don't understand what the problem is. They are just two separate relationships on the version. How would they interfere?