DALLAS — Sunday night marked the ninth combination the Islanders have tried as a fourth line in just 18 games so far this season. It also might have, finally, given them something to work with at the bottom of their lineup. The 4-1 loss to the Avalanche , with two late Colorado goals that made the final score a bit deceptive, was the first time all year that the fourth line had a case as the best for the Islanders in a game. Not so coincidentally, it was also Max Shabanov’s first game back from