Cleans up gold slime moblist code.

It will only generate the mob list once, and it won't use :  (thanks RR)

code/modules/reagents/Chemistry-Recipes.dm

@@ -21,17 +21,18 @@
 	return
 	//I recommend you set the result amount to the total volume of all components.
 
-
+var/list/chemical_mob_spawn_meancritters = list() // list of possible hostile mobs
+var/list/chemical_mob_spawn_nicecritters = list() // and possible friendly mobs
 /datum/chemical_reaction/proc/chemical_mob_spawn(datum/reagents/holder, amount_to_spawn, reaction_name, mob_faction = "chemicalsummon")
 	if(holder && holder.my_atom)
-		var/list/meancritters = list() // list of possible hostile mobs
-		var/list/nicecritters = list() // and possible friendly mobs
-		for(var/T in typesof(/mob/living/simple_animal))
-			switch(initial(T:gold_core_spawnable))
-				if(1)
-					meancritters += T
-				if(2)
-					nicecritters += T
+		if (chemical_mob_spawn_meancritters.len <= 0 || chemical_mob_spawn_nicecritters.len <= 0)
+			for (var/T in typesof(/mob/living/simple_animal))
+				var/mob/living/simple_animal/SA = T
+				switch(initial(SA.gold_core_spawnable))
+					if(1)
+						chemical_mob_spawn_meancritters += T
+					if(2)
+						chemical_mob_spawn_nicecritters += T
 		var/atom/A = holder.my_atom
 		var/turf/T = get_turf(A)
 		var/area/my_area = get_area(T)
@@ -53,9 +54,9 @@
 		for(var/i = 1, i <= amount_to_spawn, i++)
 			var/chosen
 			if (reaction_name == "Friendly Gold Slime")
-				chosen = pick(nicecritters)
+				chosen = pick(chemical_mob_spawn_nicecritters)
 			else
-				chosen = pick(meancritters)
+				chosen = pick(chemical_mob_spawn_meancritters)
 			var/mob/living/simple_animal/C = new chosen
 			C.faction |= mob_faction
 			C.loc = get_turf(holder.my_atom)