COLLEGE fashion seems usually to verge on the outrageous, but occasionally it spills over. Above, ostrich feathers sprout in profusion at a Carnival Costume Ball in the early '30s. At right, the "Shorts Rebellion," when 2,200 students cut off or rolled up their trousers in 1930, to the delight of Fox Movietone News and the horror of local observers. Below, back to your basic skin, the 1974 streaker.