FOREX-Yen hits 7-year low after BOJ expands stimulus

* BOJ's surprise easing hits yen * Dollar index near four-year highs, strong Q3 GDP growth helps LONDON, Oct 31 (Reuters) - The yen tumbled to its lowest level in nearly seven years against the dollar on Friday, putting it on track for its biggest losses in more than a year, after the Bank of Japan shocked markets by unexpectedly easing policy further. In a pre-emptive move to combat risks of ...