[Dev] recurrence behavioral kink

[Mimi Yin]

One detail I realized...

If you do something to change a single instance of a recurring event,  
thereby making it an exception (ie. Say I move the 3rd instance of a  
recurring event from a Tuesday to a Thursday)...all subsequent edits  
of that event should be automatically considered: Changes to just  
this event...

In other words, we should only pop up the annoying dialog: "Do you  
want to make these changes to Just this event or All future events?"  
once.

If the user chooses: Just this event, we should stop popping up the  
annoying dialog, even if they make further edits to the single  
excepted event.

If the user chooses: All future events, we should continue to pop up  
the annoying dialog on subsequent edits.

Mimi