Getexitdest (number)
        
   Synopsis:
      Returns the destination of an exit in the automapper's current room

   Notes:
      'number' is the position of the exit in the room's ordered list of exits
         (the first exit is numbered 1).
      The return value is the world model number of the destination room. If 
         there is no current room, if the numbered exit doesn't exist or if the 
         exit doesn't have a destination, returns 0.
      To get the number of exits in the current room, see the Getroomexits ()
         function.
