By Herbert Lash and Marc Jones NEW YORK/LONDON (Reuters) -U.S. and European stocks rallied on Monday, with the S&P 500 staying clear of a bear market, while the euro leapt after the European Central Bank said it was likely to lift its deposit rate out of negative territory by September. Oil prices slid and gold extended recent gains, but the dollar fell further as investors cut their bets on more advances in the greenback based on market expectations of yields moving higher still from Federal Reserve monetary tightening. The MSCI all-country world index gained 1.47% but is still down about 17%…