Too remove potential excessive garbage collection per tick. We will be reusing lists for overlays instead of deleting and creating them.

the .Cut() proc on a list will empty a list by default. This also will set the len to 0.

git-svn-id: http://tgstation13.googlecode.com/svn/trunk@5465 316c924e-a436-60f5-8080-3fe189b3f50e

code/game/objects/items/weapons/flamethrower.dm

@@ -48,7 +48,7 @@
 
 
 /obj/item/weapon/flamethrower/update_icon()
-	overlays = null
+	overlays.Cut()
 	if(igniter)
 		overlays += "+igniter[status]"
 	if(ptank)

code/game/objects/items/weapons/kitchen.dm

@@ -222,7 +222,7 @@
 /obj/item/weapon/tray/attack(mob/living/carbon/M as mob, mob/living/carbon/user as mob)
 
 	// Drop all the things. All of them.
-	overlays = null
+	overlays.Cut()
 	for(var/obj/item/I in carrying)
 		I.loc = M.loc
 		carrying.Remove(I)
@@ -391,7 +391,7 @@
 		foundtable = 1
 		break
 
-	overlays = null
+	overlays.Cut()
 
 	for(var/obj/item/I in carrying)
 		I.loc = loc

code/game/objects/items/weapons/secstorage/secstorage.dm

@@ -106,7 +106,7 @@
 		emagged = 1
 		src.overlays += image('icons/obj/storage.dmi', icon_sparking)
 		sleep(6)
-		src.overlays = null
+		src.overlays.Cut()
 		overlays += image('icons/obj/storage.dmi', icon_locking)
 		locked = 0
 		if(istype(W, /obj/item/weapon/melee/energy/blade))
@@ -225,7 +225,7 @@
 				src.l_set = 1
 			else if ((src.code == src.l_code) && (src.emagged == 0) && (src.l_set == 1))
 				src.locked = 0
-				src.overlays = null
+				src.overlays.Cut()
 				overlays += image('icons/obj/storage.dmi', icon_opened)
 				src.code = null
 			else
@@ -233,7 +233,7 @@
 		else
 			if ((href_list["type"] == "R") && (src.emagged == 0) && (!src.l_setshort))
 				src.locked = 1
-				src.overlays = null
+				src.overlays.Cut()
 				src.code = null
 				src.close(usr)
 			else