Alarm centralization completion

Ensures the master area is always used, to avoid issues caused by dynamic lightning which splits areas into sub-areas.
Power alarms now handled centrally.

code/modules/power/singularity/investigate.dm

@@ -1,4 +1,4 @@
-/area/engineering/poweralert(var/state, var/source)
-	if (state != poweralm)
+/area/engineering/power_alert(var/alarming)
+	if (alarming)
 		investigate_log("has a power alarm!","singulo")
 	..()