ADDFIRSTROOM ()
        
   Synopsis:
      Adds the first room to the automapper window's current region

   Notes:
      The request is performed by the automapper window, which sets the new room 
         as the current room and switches to 'update' mode.
      If the Locator task is running and knows about the current location, the
         new room will be created with matching properties (descriptions, exits
         and so on); otherwise a blank room will be created.
      If the operation is successful, the new room's world model number is
         returned. If the automapper window isn't open, if there is no current
         region, if the current region isn't empty or if the operation fails, 0
         is returned.
      See also the ADDROOM function.
