FREETOWN, Sierra Leone — Seven-year-old Ali Mansaray must build a new life for himself after surviving the mudslides and flooding that killed nearly 500 people, including his parents, in Sierra Leone last week. Now he is being looked after by his grandmother, who was spared because she was sleeping at a friend’s home the night of the Aug. 14 disaster. “The boy’s mother and father are dead. Zainab and Idrisa gave birth to him, both of them are dead now, even our neighbors,” a