remove the sub-area system

Removes area/list/related and area/master.
They were only used by the old lighting subarea system.

Signed-off-by: Mloc <colmohici@gmail.com>

code/modules/events/infestation.dm

@@ -63,11 +63,10 @@
 		//world << "	checking [areapath]"
 		var/area/A = locate(areapath)
 		//world << "	A: [A], contents.len: [A.contents.len]"
-		for(var/area/B in A.related)
 			//world << "	B: [B], contents.len: [B.contents.len]"
-			for(var/turf/simulated/floor/F in B.contents)
-				if(!F.contents.len)
-					turfs += F
+		for(var/turf/simulated/floor/F in A.contents)
+			if(!F.contents.len)
+				turfs += F
 
 	var/list/spawn_types = list()
 	var/max_number
@@ -116,4 +115,4 @@
 
 #undef VERM_MICE
 #undef VERM_LIZARDS
-#undef VERM_SPIDERS
+#undef VERM_SPIDERS