Nikkei ends down; approaches trough, says Nomura * Toyota makes modest gain on positive forecast * Gree, DeNA rebound, to scrap gambling games * Tepco surges on government capital injection, takeover By Sophie Knight     TOKYO, May 10 – Japan’s Nikkei average slid 0.4 percent on Thursday after lurching in and out of positive t e rritory as bargain hunting was offset by poor Chinese trade figures and concerns that euro zone instability could further derail global gro