(Repeats column published earlier with no changes) By Mike Dolan LONDON, March 3 (Reuters) – If skittish markets are just testing the extremes of possible central bank outcomes, policymakers who have bemoaned investor complacency for months may soon have to talk them off the cliff. To be sure, financial markets typically behave like this – probing both sides of a most likely scenario and waiting for official pushback to better define the actual policy outcome. And official indifference to sharp swings often emboldens that price search, even if some central bankers are inclined to dismiss all the action as noise – or even just ignore it. For one, new Chicago…