DALLAS — When Stars general manager Jim Nill started his third coaching search in five years, he took a look at the talented roster that is still among the youngest in the NHL. Their new coach is certainly accustomed to dealing with youth. Former University of Maine star Jim Montgomery was introduced Friday by the Stars, becoming the second head coach in three years to go directly from the college ranks to the NHL. “I think the game is changing, and in the end it’s dealing with people,” Nill said.