Yesterday's Tomorrows:: Past Visions of the American FutureEnormous skyscrapers will house residents and workers who happily go ''for weeks'' without setting foot on the ground. Streamlined, ''hurricane proof'' houses will pivot on their foundations like weather vanes. The family car will turn into an airplane so easily that ''a woman can do it in five minutes.'' Our wars will be fought by robots. And our living room furniture waterproof, of course will clean up with a squirt from the garden hose. In