When Paul O’Connor went traveling during his recent break from professorial duties in Chapel Hill, he took some serious reading matter along for company. Reviewed by Paul T. O’Connor WASHINGTON’S REVOLUTION. By Robert Middlekauff. Knopf Doubleday. 384 pages, hardcover. $30. THE LAST BATTLE. By Cornelius Ryan. Simon & Schuster. 576 pages. $18.99, paperback. Available also…