Ethan Hawke's career is distinguished by contemplative roles, notably the ones associated with Richard Linklater, though in his limited output as a director — the two narrative dramas "Chelsea Walls" and "The Hottest State" — he hasn't found the same degree of perceptive material. But that has changed with his endearing documentary "Seymour: An Introduction," a sweetly affecting portrait of creative genius existing outside of marketplace concerns that may as well serve as the actor's mission statement. Though the title echoes J.D.