Update every initialize() proc to return an initialize hint.

* Yes, all of them.
* Also did a few corrections to redundant New() and broken Destroy() along the way
* Renamed the turf_initializer.initialize() proc to InitializeTurf to avoid confusion.
* Subsumed /area/proc/initialize into /atom/proc/initialize() - Made /area's LateInitialize to get same behavior as before.

code/modules/multiz/open_space_controller.dm

@@ -61,12 +61,6 @@
 			add_turf(T)
 	open_space_initialised = TRUE
 
-/turf/simulated/open/initialize()
-	. = ..()
-	if(open_space_initialised)
-		// log_debug("[src] ([x],[y],[z]) queued for update for initialize()")
-		OS_controller.add_turf(src)
-
 /turf/Entered(atom/movable/AM)
 	. = ..()
 	if(open_space_initialised && !AM.invisibility && isobj(AM))

code/modules/multiz/structures.dm

@@ -18,6 +18,7 @@
 	var/const/climb_time = 2 SECONDS
 
 /obj/structure/ladder/initialize()
+	. = ..()
 	// the upper will connect to the lower
 	if(allowed_directions & DOWN) //we only want to do the top one, as it will initialize the ones before it.
 		for(var/obj/structure/ladder/L in GetBelow(src))
@@ -132,6 +133,7 @@
 	layer = 2.4 // Above turf, but they're sort of the floor, so below objects.
 
 /obj/structure/stairs/initialize()
+	. = ..()
 	for(var/turf/turf in locs)
 		var/turf/simulated/open/above = GetAbove(turf)
 		if(!above)

code/modules/multiz/turf.dm

@@ -34,7 +34,7 @@
 	update()
 
 /turf/simulated/open/initialize()
-	..()
+	. = ..()
 	ASSERT(HasBelow(z))
 	update()