Machinery performance tweaks (#1744)

changes:

Machines' process() has been separated from auto_use_power().
Lights no longer process() and instead use auto_use_power() for power calculations.
Computers that didn't really need to process() no longer process().
Airlocks now use the scheduler to auto-close instead of process()ing.
Fixed a bug where clicking on an AI Status display to set its status did not work.

code/modules/virus2/centrifuge.dm

@@ -78,8 +78,7 @@
 		ui.open()
 
 /obj/machinery/computer/centrifuge/process()
-	..()
-	if (stat & (NOPOWER|BROKEN)) return
+	if (inoperable()) return
 
 	if (curing)
 		curing -= 1

code/modules/virus2/curer.dm

@@ -66,9 +66,7 @@
 	return
 
 /obj/machinery/computer/curer/process()
-	..()
-
-	if(stat & (NOPOWER|BROKEN))
+	if (inoperable())
 		return
 	use_power(500)
 

code/modules/virus2/diseasesplicer.dm

@@ -86,7 +86,7 @@
 		ui.open()
 
 /obj/machinery/computer/diseasesplicer/process()
-	if(stat & (NOPOWER|BROKEN))
+	if (inoperable())
 		return
 
 	if(scanning)