Writer-director Nick Cassavetes unveiled his new movie “Yellow” at the Toronto Film Festival this weekend and found himself defending the main character’s incestuous love affair with her own brother.... “I have no experience with incest,” he told TheWrap in an interview on Sunday. “We started thinking about that. We had heard a few stories where brothers and sisters were completely, absolutely in love with one another. You know what? This whole movie is about judgment, and lack of it, and doing what you want. Love who you want. Isn’t that what we say? Gay marriage – love who you want?...