Nikkei soars on U.S. data, GPIF; Abenomics in focus after resignations

* News GPIF raising stock allocation to 25 pct underpins sentiment * Resignation of two cabinet members a big blow to Abe - analyst By Ayai Tomisawa TOKYO, Oct 20 (Reuters) - Japan's Nikkei share average surged 3.8 percent on Monday afternoon and was on track for its biggest daily rise in more than a year as investors took heart from upbeat U.S. data and as the weaker yen lifted exporters such as Toyota Motor Corp and Honda Motor Co. Also underpinning the market was news that Ja