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/modules/paperwork/clipboard.dm

@@ -35,7 +35,7 @@
 			return
 
 /obj/item/weapon/clipboard/update_icon()
-	overlays = null
+	overlays.Cut()
 	if(toppaper)
 		overlays += toppaper.icon_state
 		overlays += toppaper.overlays

code/modules/paperwork/folders.dm

@@ -23,7 +23,7 @@
 	icon_state = "folder_white"
 
 /obj/item/weapon/folder/update_icon()
-	overlays = null
+	overlays.Cut()
 	if(contents.len)
 		overlays += "folder_paper"
 	return

code/modules/paperwork/paper.dm

@@ -150,7 +150,7 @@
 	info = null
 	stamps = null
 	stamped = list()
-	overlays = null
+	overlays.Cut()
 	updateinfolinks()
 	update_icon()