- pass the handler directly
- reviewer special-cases for flags and notes are now applied at
call site
- drop the kind attribute on OpChanges which is not needed
The backend knows exactly which op has executed, and it saves us having
to re-implement this logic on each client.
Fixes the browser table refreshing when toggling decks.
Instances can pass handled_by=self to more easily ignore events they
initiate.
Fixes ugly refresh when expanding/collapsing decks, but we're still
refreshing the card/notes area unnecessarily in that case.
