* U.S. fiscal talks the big driver of global markets * U.S. Treasuries prices rise as debt talks drive safety bid NEW YORK, Nov 29 (Reuters) - U.S. stocks and the euro pared gains euro fell on Thursday as risk aversion rose after top Republican lawmaker John Boehner said there had been no substantive progress in the last two weeks in talks to reach a budget deal that would avoid the "fiscal cliff." Boehner, the speaker of the U.S. House of Representatives, said he had no idea what