Adds the moved event.

Allows movable atoms to follow other movable atoms, as quickly as BYOND allows. Also supports following atoms inside other atoms.
However, this only works fully when Move() or forceMove() is utilized. Setting loc directly will not raise the moved event.

code/modules/admin/verbs/adminjump.dm

@@ -2,7 +2,7 @@
 	return
 
 /mob/dead/observer/on_mob_jump()
-	following = null
+	stop_following()
 
 /client/proc/Jump(var/area/A in return_sorted_areas())
 	set name = "Jump to Area"