More and more these days, shopping center developers find themselves in the role of town planner. Once dedicated to creating pleasant spaces for people to shop in, they now are challenged to create places for people to live, play, eat and be entertained in. Build that, they’re told, and shoppers will come. But droves of millennials fleeing suburbs in search of more fulfilling urban lifestyles are giving developers an assist. In some cases, they’re hewing their own downtowns out of rough old sections of town. In others, old downtowns are remaking themselves to welcome this new city stock.