BOSTON — The world's oldest commissioned warship still afloat has set its sails for the last time before it heads to dry dock for a three-year repair project.The historic warship the U.S.S. Constitution left its berth at the Charlestown Navy Yard in Boston on Friday morning. It set and struck three topsails and then fired a 21-gun salute off Castle Island in South Boston.The Constitution will get underway for the final time before the repair job on Oct.