Barbra Streisand and Ryan O'Neal star in this Peter Bogdanovich salute to the    screwball comedy. She's a nutcase and he's a very absent-minded musicologist.    Together they upset quite a few people in San Francisco. With Madeline Kahn      (in her screen debut), Kenneth Mars and Liam Dunn.                             Peter Bogdanovich---USA---1972---94 mins.