Functions MAIL and DIRED now use ZMACS.

[RMS at MIT-OZ]

Starting in 93.15, the functions MAIL and DIRED now use a ZMACS
frame to do the editing, rather than a special-purpose window.
They know how to find a ZMACS frame which is idle waiting for
commands, or to create one if necessary.

Some of the advantages include the ability to switch from
the one directory or message to other things without any more
window switching.  However, there are various reasons people
might not like this--I can't tell.  Therefore, there is a variable
ZWEI:*MAIL-AND-DIRED-USE-ZMACS*, which if set to NIL brings
back the old behavior.

I would like to know whether anyone dislikes the new way,
and, if so, why.  I would like to flush the complexity of
providing the old way if nobody can point to a reason for it.
Or make it the default again if there is a reason for it.
-------