DALLAS, March 20, 2008 (AP) -- Ray Allen was sitting on the bench in the fourth quarter, arms crossed and a black shirt over his jersey. He was forced to watch James Posey take his place, just like he'd done the last few nights in Houston and San Antonio.With 1:54 left, Allen finally got in. And with 31.7 seconds to go, he nailed the 3-pointer that capped a fun few days in the Lone Star State.Allen's go-ahead jumper sent Boston past Dallas 94-90 Thursday night, making the Celtics the first team to go 3-0 on a Texas road swing since the Sacramento Kings in November 2001. Along the way, they gave the Spurs their first home loss in six weeks, ended Houston's 22-game winning streak and stuck the Mavericks with just their sixth home loss of the season."This feels good,'' said Allen, who'd missed three games with a jammed left ankle. "It's something for the rest of the NBA to watch.''Boston upped its NBA-best record to 55-13 while...