By Gertrude Chavez-Dreyfuss and Amanda Cooper NEW YORK/LONDON (Reuters) – The dollar soared against the yen on Friday, on track for its largest daily gain in roughly two weeks, after the Bank of Japan governor repeated that the central bank will maintain its ultra-loose monetary policy amid speculation an imminent shift is coming. BOJ Governor Haruhiko Kuroda, who addressed the World Economic Forum in the Swiss town of Davos on Friday, said the central bank will continue its current “extremely accommodative” monetary policy to achieve its 2% inflation target in a stable, sustainable manner. Sp…