A century ago, one section of Vienna played host to Adolf Hitler, Leon Trotsky, Joseph Tito, Sigmund Freud and Joseph Stalin. In January 1913, a man whose passport bore the name Stavros Papadopoulos disembarked from the Krakow train at Vienna's North Terminal station. Of dark complexion, he sported a large peasant's moustache and carried a very basic wooden suitcase. "I was sitting at the table,"