GLOBAL MARKETS-Stocks slump as ECB disappoints, U.S. rate debate rages

* Europe stocks slump after ECB disappoints* Wall Street edges lower after global sell-off* Tokyo stocks hit hard, safe-haven yen, gold benefit* Oil plunges as Saudi producers jump into supply battleBy Marc JonesLONDON, Oct 2 (Reuters) - World stocks were knocked hard on Thursday as signs of a strengthening U.S. jobs market stirred concerns about U.S. rate rises and the ECB failed to convince mark