By MIKE HEIKA DENVER — There was a painful silver cloud for the Dallas Stars on Thursday after they saw an end to their five-game winning streak.After the Stars were felled 3-2 by the Colorado Avalanche in a dull game at a half-full Pepsi Center, Dallas players and coaches bemoaned the fact that they missed a great opportunity by not giving their best effort."The good thing about a winning streak is you set new standards, and that wasn’t even close to the standard we’ve been playing," Stars coach Dave Tippett said.