Concept of changes

[hvitis]

This is just a concept of changes. (not tested and not fully implemented)

I'm mostly wondering about your idea that you mentioned in the Issue. I'm not sure about the sentbox. I see that there is a sender but only in Message model (which sometimes can be deleted as a first object by default?) Maybe that is why it could be OK just to add sent_by or created_by FK on the Thread model so that we can easily query when calling sentbox?

Also I changed the URLs to unify the structure and get rid of the words (We use HTTP methods). It could be unified even more. This way we know that the root is threads and we follow the convention for listing on root / etc.

Relates to.