Stocks Slide As Oil Nears \$50 a Barrel NEW YORK - Oil prices reached a new high and sent stocks lower Monday, but with trading on Wall Street light and losses only moderate, investors seemed to be coming to terms with near-\$50 per barrel crude.    After setting a new all-time record settlement price of \$48.88 on Friday, oil continued its march higher on Monday, renewing fears on Wall Street that the slowdown in profits and the economic recovery would extend through the end of the year due to high energy costs...