[RFA] Make QUIT work

[Michael Snyder]

Joel Brobecker wrote:
See the patch Joel submitted for this last August.  Elena deferred it
to after 6.1 because just setting quit_flag invokes both sets of event
handling machinery, potentially quitting twice.


Yes, I look at this a little bit more after you reviewed my patch,
and omigod yes, it quits twice. And unfortunately, I wasn't too sure
by reading the code how this should be made to work (wasn't able to
deduce the design, CRC too weak :-).
We're after 6.1 BTW :-) but poor Elena seems to be drowned with other
stuff, we've hardly seen any message from her for a while :-/.
OK, I see the "quit twice" problem too, but it leads one to ask:
which is worse?  Quitting once too often, or not quitting at all?
Right now, in some situations at least, you can't quit at all.
That's bad.