! Copyright (c) 1990-1997  Michael Sandrof, Troy Rollo, Matthew Green,
! and other ircII contributors.
!
! All rights reserved.  See the HELP IRCII COPYRIGHT file for more
! information.
!
Usage: WINDOW BACK
  Set the current window to the previous current window
  swapping the current window with the new one if it was
  hidden.
