Setroomtagged ()
Setroomtagged (string)

   Synopsis:
      Sets the tagged room as the automapper's current room

   Notes:
      'string' is the tag of a world model room, such as 'tower'. If 'string'
         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 tagged room is specified. Returns 0 if
         'string' isn't a recognised room tag or if the set/unset operation
         fails.
      See also the Setroomnum () function.
