It might be a stretch to claim that all the children at Sunday's Boston Comic Con were present to support their parents, but there was one incontrovertible example. Two toddlers, swaddled in the costumes of Superman and the Flash, raced through the Back Bay Events Center in strollers, pushed by their parents. "I think he's going to win," said the mother, pointing at the one dressed as Superman. "He's really the fastest." The convention was......