As Carol Channing, clad in a Bob Mackie sleeveless pantsuit, chinchilla (?) wrap, bright red lipstick, and a 77-karat diamond said last night: "Musical theater is a strictly American art form." The ladies who helped forge that - along with movies and television - were being feted by The Smithsonian, who were specifically honoring women who have woven their way into the American cultural fabric, welcoming their treasured memorabilia into the Smithsonian's permanent collection. There......