* U.S. optimism of fiscal deal boosts markets * European shares climb 0.5 pct adding to rises in Asia * Euro steadies vs dollar, dollar up vs yen * Commodities recover By Marc Jones LONDON, Nov 29 (Reuters) - World shares hit three-week peaks and commodities were also higher on Thursday as comments from a senior U.S. lawmaker raised hopes of a budget deal by year-end to avoid a fiscal crisis in the world's biggest economy. With Asian shares higher and the FTSEurofirst 30