Mr. Churchill in the White HouseWell into the twenty first century, Winston Churchill continues to be the subject of scores of books. Biographers portray him as a soldier, statesman, writer, painter, and even a daredevil, but Robert Schmuhl, the noted author and journalist, may be the first to depict him as a demanding, indeed exhausting White House guest. For the British prime minister, America's most famous residence was "the summit of the United States," and staying weeks on end