Twitter has not been a happy forum for John Cleese, whose foray onto social media has transformed him from national treasure to eccentric old weirdo. The Hacked Off divorce enthusiast this morning tweeted that he hoped Paul Dacre’s next heart attack “is his last”. Dacre has a heart condition. Last year Guido caught Cleese comparing journalists to murderers – he first denied he’d said it then fessed up and claimed he was joking. Step away from the keyboard…