BOSTON (AP) — Microsoft on Wednesday rolled out new features on its Bing search engine powered by artificial intelligence, including one that summarizes the two opposing sides of contentious questions, and another that measures how many reputable sources are behind a given answer. Tired of delivering misleading information when their algorithms are gamed by trolls and purveyors of fake news, Microsoft and its tech-company rivals have been going out of their way to show they can be purveyors of good information — either by using better algorithms or hiring more human moderators.