This is a major change to draft internals. Previously there were quite a
few cases where the draft system would say "draft saved", when in fact
we just skipped saving.
This commit ensures the draft system deals with draft ownership handover in
a predictable way.
For example:
- Window 1 editing draft
- Window 2 editing same draft at the same time
Previously we would allow window 1 and 2 to just fight on the same draft
each window overwriting the same draft over an over.
This commit introduces an ownership concept where either window 1 or 2 win
and user is prompted on the loser window to reload screen to correct the issue
This also corrects edge cases where a user could have multiple browser windows
open and posts in 1 window, later to post in the second window. Previously
drafts would break in the second window, this corrects it.
