Split and clarify global lists of processing vs non-processing machinery. (#5307)

* Renaming local var 'machines' to avoid confusion with the global var of same name.

* Delete the unused process scheduler machinery.dm file.  Long since replaced with SSmachines

* Split and clarify global lists of processing vs non-processing machinery.

- Renamed the list of processing machinery from "machines" to "processing_machines"
- Added new global list "machines" to be a list of all machines.
- Since nearly every reference to machines actually wanted to iterate over all machines anyway, this works out great.

code/controllers/Processes/machinery.dm

@@ -1,67 +0,0 @@
-/var/global/machinery_sort_required = 0
-
-/datum/controller/process/machinery/setup()
-	name = "machinery"
-	schedule_interval = 20 // every 2 seconds
-	start_delay = 12
-
-/datum/controller/process/machinery/doWork()
-	internal_sort()
-	internal_process_pipenets()
-	internal_process_machinery()
-	internal_process_power()
-	internal_process_power_drain()
-
-/datum/controller/process/machinery/proc/internal_sort()
-	if(machinery_sort_required)
-		machinery_sort_required = 0
-		machines = dd_sortedObjectList(machines)
-
-/datum/controller/process/machinery/proc/internal_process_machinery()
-	for(last_object in machines)
-		var/obj/machinery/M = last_object
-		if(M && !QDELETED(M))
-			if(M.process() == PROCESS_KILL)
-				//M.inMachineList = 0 We don't use this debugging function
-				machines.Remove(M)
-				continue
-
-			if(M && M.use_power)
-				M.auto_use_power()
-
-		SCHECK
-
-/datum/controller/process/machinery/proc/internal_process_power()
-	for(last_object in powernets)
-		var/datum/powernet/powerNetwork = last_object
-		if(istype(powerNetwork) && !QDELETED(powerNetwork))
-			powerNetwork.reset()
-			SCHECK
-			continue
-
-		powernets.Remove(powerNetwork)
-
-/datum/controller/process/machinery/proc/internal_process_power_drain()
-	// Currently only used by powersinks. These items get priority processed before machinery
-	for(last_object in processing_power_items)
-		var/obj/item/I = last_object
-		if(!I.pwr_drain()) // 0 = Process Kill, remove from processing list.
-			processing_power_items.Remove(I)
-		SCHECK
-
-/datum/controller/process/machinery/proc/internal_process_pipenets()
-	for(last_object in pipe_networks)
-		var/datum/pipe_network/pipeNetwork = last_object
-		if(istype(pipeNetwork) && !QDELETED(pipeNetwork))
-			pipeNetwork.process()
-			SCHECK
-			continue
-
-		pipe_networks.Remove(pipeNetwork)
-
-/datum/controller/process/machinery/statProcess()
-	..()
-	stat(null, "[machines.len] machines")
-	stat(null, "[powernets.len] powernets")
-	stat(null, "[pipe_networks.len] pipenets")
-	stat(null, "[processing_power_items.len] power item\s")