Destroy() cleanups in VOREStation code

* Remove remaining hard del()'s in our code.
* Replace deleted() and gcDestroyed with QDELETED macro.
* Fix some strange calls directly to Del() (capital D)
* Make Destroy() return qdel hints.
* Make a few of the Destroy()'s more comprehensive in cleaning up references.
* In edited Destroy() procs, converted to use qdel_null and qdel_null_list macros when possible for pretty code.
* Removed unused variable `sleevecard`

code/modules/vore/resizing/holder_micro_vr.dm

@@ -34,4 +34,4 @@
 	var/turf/here = get_turf(src)
 	for(var/atom/movable/A in src)
 		A.forceMove(here)
-	..()
+	return ..()