Four major superheroes have new movies this year. Superman gets a reboot in June's "Man of Steel," the deadly claws of "The Wolverine" spring back out in July, and Thor will swing his hammer in November's "Thor: The Dark World." But the liveliest of the current superhero franchises arrives Friday, as "Iron Man 3" hits theaters.Thanks in no small part to its star, the can't-take-your-eyes-off-him R...