By Marc Jones LONDON (Reuters) - The dollar slipped to a 12-week low on Thursday and stock and bonds markets both showed caution after the U.S. Federal Reserve stuck to its mildly upbeat view of the world but gave no hint on when it will next raise interest rates. Rabobank analyst Michael Every said despite tweaks in the Fed's statement, including that inflation "will", rather than "is expected to" rise to 2 percent, it could be taken as broadly dovish. "There was not the spoon-feeding ‘expect a rate hike in March’ guidance the market has come to expect (from the Fed) before such changes in policy are made," he said.