Gen 5 Repel system

Also used in PureRGB. Gives the player the option to use another Repel after the last one runs out.

I had to remove some debug features in order to fit it in, but it won't have an effect on the regular game. Hopefully.

engine/items/get_bag_item_quantity.asm

@@ -16,3 +16,23 @@ GetQuantityOfItemInBag:
 .notInBag
 	ld b, 0
 	ret
+
+GetIndexOfItemInBag:
+; In: b = item ID
+; Out: b = index of item in bag (FF if not)
+	call GetPredefRegisters
+	ld hl, wBagItems - 1
+	ld c, -1
+.loop
+	inc c
+	inc hl
+	ld a, [hli]
+	cp $ff
+	jr z, .notInBag
+	cp b
+	jr nz, .loop
+	ld b, c
+	ret
+.notInBag
+	ld b, a
+	ret