Replace global all_areas list with world.

It ends up having similar performance, so might as well not bother with all_areas.

code/modules/admin/secrets/random_events/gravity.dm

@@ -16,7 +16,7 @@
 		return
 
 	gravity_is_on = !gravity_is_on
-	for(var/area/A in all_areas)
+	for(var/area/A in world)
 		A.gravitychange(gravity_is_on)
 
 	feedback_inc("admin_secrets_fun_used",1)

code/modules/admin/verbs/debug.dm

@@ -341,7 +341,7 @@
 	var/list/areas_with_intercom = list()
 	var/list/areas_with_camera = list()
 
-	for(var/area/A in all_areas)
+	for(var/area/A in world)
 		if(!(A.type in areas_all))
 			areas_all.Add(A.type)
 

code/modules/events/gravity.dm

@@ -15,7 +15,7 @@
 
 /datum/event/gravity/start()
 	gravity_is_on = 0
-	for(var/area/A in all_areas)
+	for(var/area/A in world)
 		if(A.z in zLevels)
 			A.gravitychange(gravity_is_on)
 
@@ -23,7 +23,7 @@
 	if(!gravity_is_on)
 		gravity_is_on = 1
 
-		for(var/area/A in all_areas)
+		for(var/area/A in world)
 			if(A.z in zLevels)
 				A.gravitychange(gravity_is_on)
 

code/modules/events/prison_break.dm

@@ -41,7 +41,7 @@
 
 
 /datum/event/prison_break/start()
-	for(var/area/A in all_areas)
+	for(var/area/A in world)
 		if(is_type_in_list(A,areaType) && !is_type_in_list(A,areaNotType))
 			areas += A
 

code/modules/lighting/lighting_setup.dm

@@ -1,6 +1,6 @@
 // Create lighting overlays on all turfs with dynamic lighting in areas with dynamic lighting.
 /proc/create_all_lighting_overlays()
-	for(var/area/A in all_areas)
+	for(var/area/A in world)
 		if(!A.dynamic_lighting)
 			continue
 		for(var/turf/T in A)

code/modules/maps/tg/reader.dm

@@ -346,7 +346,7 @@ var/global/use_preloader = FALSE
 		var/atom/instance
 		_preloader.setup(members_attributes[index])//preloader for assigning  set variables on atom creation
 		var/atype = members[index]
-		for(var/area/A in all_areas)
+		for(var/area/A in world)
 			if(A.type == atype)
 				instance = A
 				break