Method moveNext

fdbserver/KeyValueStoreSQLite.actor.cpp:755–759

		valid = !empty;
	}
	void moveNext() {
		int empty = 1;
		db.checkError("BtreeNext", sqlite3BtreeNext(cursor, &empty));
		valid = !empty;
	}
	void movePrevious() {
		int empty = 1;
		db.checkError("BtreePrevious", sqlite3BtreePrevious(cursor, &empty));