Film will introduce 'Civil War' plot line It looks like Robert Downey Jr. will be putting the Iron Man suit back on again for some big roles in the Marvel universe. According to Variety, Downey is close to signing on to play Iron Man in Captain America 3, taking up a significant role in the film that will help it introduce a new phase of Marvel movies.The film will reportedly find Iron Man and Captain America feuding over a law called the Superhero Registration Act, which requires heroes to register with the US government to do its bidding. Iron Man is...