SHAREMENU GuiName

  This command will allow a gui (call it Gui1) to share the menus 
  of an other gui (call it Gui2).

  > ShareMenu Gui2

  When Gui1 is opened, it will have the same menus as Gui2.

  When a menu is selected it will be as if the menus of Gui2 was
  selected and all commands attached to it will be executed.

  The gui whose menus are being shared by others will *not* be 
  allowed to quit unless all the sharers have been closed first,
  since we need it's commands.

  Gui4Cli will look for Gui2 when Gui1 tries to open - not when it
  tries to load itself. So when Gui1 is closed, Gui2 is free to
  quit (unless there are other open guis sharing it's menus).

  If Gui2 is not found when Gui1 tries to open, Gui1 will open
  without menus.

  The best way of using this in a multi-gui application would be
  to have a menu-only file that you would load and let all guis
  share it.