By Jonathan Spicer and Alister Bull (Reuters) - Federal Reserve policymakers went out of their way on Saturday to play down the risk that aggressive measures to bolster the U.S. economy would lead to inflation in the future, in a clear signal of support for its ongoing actions to spur growth. The U.S. central bank last month maintained a controversial program of buying $85 billion of bonds a month, while pledging to keep interest rates near zero until unemployment hits at least 6.5 percent, so long as inflation stays under 2.5 percent. ...