Used by the routine at 31746. Bit set=got, bit reset=haven't.

Bit	Item	Set	Reset	Checked
0	Safe key	30804		23907, 30804
1	Science Lab storeroom key	24028		24028, 29681, 30229, 31254
2	Frog	31733	29462	29462
3	Water pistol (with water if bit 4 reset)	62178	23863	23863, 23907, 63898
4	Water pistol with sherry	23907	23863	23863, 23907, 63898, 64077
5	3 stinkbombs	62178	63586
6	2 stinkbombs	62178	63586
7	1 stinkbomb	62178	63586	28992