Scott Butera has earned a reputation as a casino turnaround artist in the gambling world. He navigated financial messes at Trump Hotels & Casino Resorts and Tropicana Entertainment, leading both out of bankruptcy. As chief executive of Foxwoods, Butera has overseen the restructuring of more than $2 billion in debt. But Butera has never built a casino from scratch, as he hopes to do on a 177-acre tract off Interstate 495 in Milford.