A Coco Chanel ballet slipper, Beethoven’s hair, Andy Warhol’s painted ticket. “Treasures,” at the New York Public Library, showcases delights from its collections.A Coco Chanel ballet slipper, Beethoven’s hair, Andy Warhol’s painted ticket. “Treasures,” at the New York Public Library, showcases delights from its collections.Read MoreLibraries and Librarians, Art, New York Public Library, Dickens, Charles, Marx, Anthony W, LaGuardia, Fiorello H