Add a peek flag -p to the view commands to open the message viewer
without setting the "seen" flag. If the flag is set, it would ignore the
"auto-mark-read" config.
The SetSeen flag will be propagated in case the message viewer moves on
to other messages, i.e. with the delete or archive commands.
Signed-off-by: Koni Marti <koni.marti@gmail.com>
Acked-by: Robin Jarry <robin@jarry.cc>