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/devices/PDA/PDA.dm

@@ -893,7 +893,7 @@ var/global/list/obj/item/device/pda/PDAs = list()
 
 		if("Toggle Door")
 			if(cartridge && cartridge.access_remote_door)
-				for(var/obj/machinery/door/blast/M in world)
+				for(var/obj/machinery/door/blast/M in machines)
 					if(M.id == cartridge.remote_door_id)
 						if(M.density)
 							M.open()

code/game/objects/items/devices/PDA/cart.dm

@@ -468,7 +468,7 @@ var/list/civilian_cartridges = list(
 		else
 			JaniData["user_loc"] = list("x" = 0, "y" = 0)
 		var/MopData[0]
-		for(var/obj/item/weapon/mop/M in world)
+		for(var/obj/item/weapon/mop/M in all_mops)
 			var/turf/ml = get_turf(M)
 			if(ml)
 				if(ml.z != cl.z)
@@ -481,7 +481,7 @@ var/list/civilian_cartridges = list(
 
 
 		var/BucketData[0]
-		for(var/obj/structure/mopbucket/B in world)
+		for(var/obj/structure/mopbucket/B in all_mopbuckets)
 			var/turf/bl = get_turf(B)
 			if(bl)
 				if(bl.z != cl.z)
@@ -493,7 +493,7 @@ var/list/civilian_cartridges = list(
 			BucketData[++BucketData.len] = list("x" = 0, "y" = 0, dir=null, status = null)
 
 		var/CbotData[0]
-		for(var/mob/living/bot/cleanbot/B in world)
+		for(var/mob/living/bot/cleanbot/B in mob_list)
 			var/turf/bl = get_turf(B)
 			if(bl)
 				if(bl.z != cl.z)
@@ -505,7 +505,7 @@ var/list/civilian_cartridges = list(
 		if(!CbotData.len)
 			CbotData[++CbotData.len] = list("x" = 0, "y" = 0, dir=null, status = null)
 		var/CartData[0]
-		for(var/obj/structure/janitorialcart/B in world)
+		for(var/obj/structure/janitorialcart/B in all_janitorial_carts)
 			var/turf/bl = get_turf(B)
 			if(bl)
 				if(bl.z != cl.z)

code/game/objects/items/devices/paicard.dm

@@ -1,3 +1,5 @@
+GLOBAL_LIST_BOILERPLATE(all_pai_cards, /obj/item/device/paicard)
+
 /obj/item/device/paicard
 	name = "personal AI device"
 	icon = 'icons/obj/pda.dmi'

code/game/objects/items/devices/radio/beacon.dm

@@ -6,6 +6,8 @@
 	var/code = "electronic"
 	origin_tech = list(TECH_BLUESPACE = 1)
 
+GLOBAL_LIST_BOILERPLATE(all_beacons, /obj/item/device/radio/beacon)
+
 /obj/item/device/radio/beacon/hear_talk()
 	return