By Samantha Sunne NEW YORK (Reuters) – Brent crude oil prices dipped on Wednesday, threatening to touch new six-year lows after an unexpected big rise in U.S. crude and fuel inventories and a dimmer view of world economic growth next year. U.S. crude prices gained despite the stockbuild, threatening to once again reach parity to the European marker as dealers bid for barrels to put into storage, taking advantage of a widening gap between depressed short-term prices and higher longer-term ones. …