As the monster hit film Iron Man comes to DVD this week -- and Marvel and Paramount reach a deal for distributing such films as Iron Man 2 -- it is a good time to catch up with comic-book writer MATT FRACTION. The 32-year-old writer, who co-founded Artbomb and Savant, teamed with Salvador Larroca this year for Invincible Iron Man, Marvel's story designed as an entry point for fans who became