Crude oil futures edged up on Wednesday, but were still not far off 6-1/2 year lows after China's central bank moved to support the country's stumbling economy, while concerns about a supply glut capped gains. Asian stocks shook off early weakness to race higher on Wednesday, led by battered Chinese shares even as worries lingered on whether China's actions would be enough to stabilize its cooling economy or halt a collapse in its stock markets.