‘Thor’ remains a box office smash, thundering into second weekend

After a smashing start in its first weekend in theaters, “Thor: Ragnarok” thundered to the box office top spot once again this week, taking $56.6 million, according to industry estimates released Sunday. The third “Thor” episode, boosted by the self-mocking humor of Chris Hemsworth as the powerful Norse god (alongside Cate Blanchett as Hela, goddess of…