MEET THE NEWMANS, J. NivenFor two decades, Del and Dinah Newman and their sons, Guy and Shep, have ruled television as Americas Favorite Family. Millions of viewers tune in every week to watch them play flawless, black and white versions of themselves. But now its 1964, and the Newmans idealized apple pie perfection suddenly feels woefully out of touch. Ratings are in free fall, as are the Newmans themselves. Del is keeping an explosive secret from his wife, and Dinah is