Michael Gunn talks to Cody Brotter about being in Aaron Sorkin\u2019s writer\u2019s room fro \u201cThe Newsroom,\u201d writing and pitching (and selling) feature-length screenplays, getting on The Black List, working in casting at HBO, and writing on \u201cThe Whispers,\u201d \u201cBlack Sails,\u201d and \u201cDesignated Survivor.\u201d