STANSTEAD, Quebec (AP) — For more than 100 years, people in Stanstead, Quebec have been able to walk into Derby Line, Vermont to enter the border-straddling Haskell Free Library and Opera House – no passport required. But municipal and library officials said on Friday that U.S. authorities have unilaterally decided to end the century-old unwritten agreement. Coming at a time of heightened tensions between the two countries, the decision is prompting an outpouring of emotion in communities on both sides of the border, which in places has been marked simply by flower pots. Inside the library celebrated as a symbol...