NEW YORK — Amid the bright lights and electronic billboards of New York’s Times Square, city authorities are posting signs proclaiming the bustling crossroads a “Gun Free Zone.”The sprawling Manhattan tourist attraction is one of scores of “sensitive” places — including parks, churches and theaters — that will be off-limits for guns under a sweeping new state law going into effect Thursday. The measure, passed after a U.S. Supreme Court decision in June expanded gun rights …