for(var/bad_code in world)

Removes a very large amount of world loops.
Adds a macro to painlessly generate a global list, and the needed code to modify the list when an object is made or deleted automatically.
Cleans up some commented out code.

code/game/objects/items/weapons/implants/implant.dm

@@ -69,6 +69,8 @@
 	else
 		..()
 
+GLOBAL_LIST_BOILERPLATE(all_tracking_implants, /obj/item/weapon/implant/tracking)
+
 /obj/item/weapon/implant/tracking
 	name = "tracking implant"
 	desc = "An implant normally given to dangerous criminals. Allows security to track your location."
@@ -309,6 +311,8 @@ Implant Specifics:<BR>"}
 			explosion(get_turf(imp_in), -1, -1, 1, 3)
 			qdel(src)
 
+GLOBAL_LIST_BOILERPLATE(all_chem_implants, /obj/item/weapon/implant/chem)
+
 /obj/item/weapon/implant/chem
 	name = "chemical implant"
 	desc = "Injects things."