More belt overlays

I posted in PR #4548 that I'd like to try and make the other belt overlays. Here is my contribution!

Progress
- [x] Bandolier
- [x] Botany belt
- [ ] Utility belt
- [ ] Medical belt
- [ ] Janitor belt
- [ ] Holtser(?)
- [ ] Soulstone belt(?)

Bandolier works the same as the lazarus "trainer's belt". I had to remove the bottom shell pixels so that it actually held eight instead of nine shells.

Botany belt shows icons for plant analyzer, mini hoe, spade, hatchet, and wirecutters. Wirecutters will be shared with botany belt and utility belt.

code/game/objects/items/weapons/storage/belt.dm

@@ -44,6 +44,7 @@
 	desc = "Can hold various tools."
 	icon_state = "utilitybelt"
 	item_state = "utility"
+	use_item_overlays = 1
 	can_hold = list(
 		"/obj/item/weapon/crowbar",
 		"/obj/item/weapon/screwdriver",
@@ -90,6 +91,7 @@
 	desc = "Can hold various medical equipment."
 	icon_state = "medicalbelt"
 	item_state = "medical"
+	use_item_overlays = 1
 	can_hold = list(
 		"/obj/item/device/healthanalyzer",
 		"/obj/item/weapon/dnainjector",
@@ -129,6 +131,7 @@
 	desc = "Can hold various botanical supplies."
 	icon_state = "botanybelt"
 	item_state = "botany"
+	use_item_overlays = 1
 	can_hold = list(
 		"/obj/item/device/analyzer/plant_analyzer",
 		"/obj/item/weapon/minihoe",
@@ -240,6 +243,7 @@
 	item_state = "janibelt"
 	storage_slots = 6
 	max_w_class = 4 // Set to this so the  light replacer can fit.
+	use_item_overlays = 1
 	can_hold = list(
 		"/obj/item/weapon/grenade/chem_grenade/cleaner",
 		"/obj/item/device/lightreplacer",
@@ -310,6 +314,21 @@
 	new /obj/item/ammo_casing/shotgun/beanbag(src)
 	new /obj/item/ammo_casing/shotgun/beanbag(src)
 
+/obj/item/weapon/storage/belt/bandolier/update_icon()
+	..()
+	icon_state = "[initial(icon_state)]_[contents.len]"
+
+/obj/item/weapon/storage/belt/bandolier/attackby(obj/item/W, mob/user)
+	var/amount = contents.len
+	. = ..()
+	if(amount != contents.len)
+		update_icon()
+
+/obj/item/weapon/storage/belt/lazabandolierrus/remove_from_storage(obj/item/W as obj, atom/new_location)
+	..()
+	update_icon()
+
+
 /obj/item/weapon/storage/belt/holster
 	name = "shoulder holster"
 	desc = "A holster to conceal a carried handgun. WARNING: Badasses only."