Stocks Higher As Oil Nears \$50 a Barrel NEW YORK - Stocks moved slightly higher Friday as investors tried to uncouple share prices from skyrocketing oil costs, even as crude reached new highs and flirted with \$50 per barrel.    A barrel of light crude was quoted at \$48.90, up 20 cents, on the New York Mercantile Exchange after setting a new intraday record earlier in the session at \$49.40...