No need to re-render the view on annotation save

The view data is up-to-date with whatever the user entered already
and a re-render will happen again when the permanent id and timestamps
return from the server anyway.
Just some code commenting
Always show share/edit/etc to reduce jumpiness

Re-introduce the flash messages when attempting to reply to and
share unsaved annotations. Doing so is better than hiding them
because hiding them results in newly created annotations changing
layout when the id is returned from the server.