Getexitdrawn$ (number)

   Synopsis:
      Returns the direction in which an exit is drawn on the map

   Notes:
      Exits are drawn in one of eighteen primary directions - the sixteen
         cardinal directions plus 'up' and 'down'.
      'number' is the position of the exit in the current room's ordered list of
         exits (the first exit is numbered 1).
      If there is no current room, if the numbered exit doesn't exist or if it
         hasn't been allocated a primary direction (not even a temporary one),
         returns an empty string.
      To get the number of exits in the current room, see the Getroomexits ()
         function.
      To get the exit's actual direction, see the Getexit$ () function.
