DEIR AL-BALAH, Gaza Strip — Hamas released all 20 remaining living hostages held in Gaza on Monday, as part of a ceasefire pausing two years of war that pummeled the territory , killed tens of thousands of Palestinians, and had left scores of captives in militant hands. Palestinians, meanwhile, awaited the release of more than 1,900 of prisoners held by Israel, with the first two buses leaving Ofer Prison in the early afternoon. The 20 hostages, all men, arrived back Israel, where they will