"The thing about Doctor Who is, it's a tremendously flexible show," departing showrunner Steven Moffat says of the long-running Time Lord series soon launching its 13th Doctor and first woman in the role of the dual-hearted Gallifreyan. "It's tremendously light on its feet, and being tremendously light on its feet means it also changes episode to episode as opposed to just era to era, you know," the Emmy-winning Sherlock EP adds on the eve of Doctor Who's Comic-Con…