Hugh Bonneville plays the lord of the manor on “Downton Abbey” with the kind of fierce rectitude that would cause us shock if he even thought, much less muttered, a four-letter word. Not the case on “Twenty Twelve,” the quite raucous comedy now running on the BBC. In it Bonneville plays Ian Fletcher, Head of Deliverance of the Olympic Deliverance Commission — the group tasked with organizing the Games. Fletcher swears like a sailor, as you’ll see in the above clip. Doubtful that the show will be broadcast legally in the U.S., as it concerns the run-up to the London Olympics, which will seem stale bread in a month’s time.