By Herbert Lash NEW YORK (Reuters) – Stocks slid in Europe and on Wall Street while safe-haven government debt prices rose after hopes diplomacy might resolve the Ukraine crisis gave way on news of increased shelling in the country’s east and a tough stance from Russia. European shares erased earlier gains and the ruble slipped sharply from a session high after a separatist leader in eastern Ukraine announced the evacuation of his breakaway region’s residents to Russia, a shock turn in the crisis. The dollar rebounded and the safe-haven Swiss franc rose as sentiment that had improved on news l…