Alt head tweaks

Todo: CMA/morph support for alt heads.
Known issues: Can't change alt head on the fly, icon won't update
properly

code/modules/surgery/organs/organ_icon.dm

@@ -141,10 +141,7 @@ var/global/list/limb_icon_cache = list()
 			else
 				if(limb_name == "head")
 					var/obj/item/organ/external/head/head_organ = src
-					if(head_organ.alt_head)
-						var/datum/sprite_accessory/alt_heads/alternate_head = alt_heads_list[head_organ.alt_head]
-						if(alternate_head.icon_state)
-							icon_name = alternate_head.icon_state
+					head_organ.handle_alt_icon()
 
 				if(status & ORGAN_MUTATED)
 					mob_icon = new /icon(species.deform, "[icon_name][gender ? "_[gender]" : ""]")

code/modules/surgery/organs/subtypes/standard.dm

@@ -194,3 +194,9 @@
 				disfigure("brute")
 		if(burn_dam > 40)
 			disfigure("burn")
+
+/obj/item/organ/external/head/proc/handle_alt_icon()
+	if(alt_head)
+		var/datum/sprite_accessory/alt_heads/alternate_head = alt_heads_list[alt_head]
+		if(alternate_head.icon_state)
+			icon_name = alternate_head.icon_state