“Either they kill us or we kill them” reads the headline on the first page of the May 4 New York Times quoting a member of a violent gang in Honduras.It echoed in spirit, if not in exact words, how in New York City circa 1957, the leader of a Puerto Rican gang known as the Sharks described its clash of mutual hatred with the Irish, Polish and Italian Jets in the classic “West Side Story.”The Lyric Opera of Chicago, continuing its fine tradition of showing not only great opera but also the best of …