‘Last Tango in Halifax’: Love, Aged to Perfection

The rekindling of long-lost love is at the center of Last Tango in Halifax, the sterling new drama premiering Sunday at 8 p.m. on PBS stations (check local listings). Already a hit in the U.K. – it won Best Drama Series at this year’s British Academy Television Awards – it arrives in the U.S. just a few weeks before the start of a new network-TV season. It’s easily the fall’s best new series, albeit a short one: just six episodes. …