Stock futures slipped early Wednesday, mirroring losses overseas as global markets position for possible "fiscal cliff"-related tax and budget changes at year end. Dow futures were off 36 points and falling. Nasdaq 100 futures dimmed eight points. S&P 500 futures were 5.2 points into the red. In stocks, Green Mountain Coffee Roasters (GMCR) earns the premarket afterburner award, up 23% ahead of the bell. The coffee wholesaler and Keurig,