Setroomnum ()
Setroomnum (number)
        
   Synopsis:
      Sets the automapper's current room

   Notes:
      'number' is the world model number of a room, such as 99. If 'number' 
         isn't specified, the current room (if any) is unset.
      Returns 1 if the specified room is set as the current room, or if the
         current room is unset when no room is specified. Returns 0 if 'number'
         isn't a valid room model number or if the set/unset operation fails.
      See also the Setroomtagged () function.
