Merge pull request #6043 from Heroman3003/zshadow-fixes

Fixes way elevator handles deleting z-shadows

code/modules/multiz/zshadow.dm

@@ -24,6 +24,7 @@
 	sync_icon(L)
 
 /mob/zshadow/Destroy()
+	owner.shadow = null
 	owner = null
 	..() //But we don't return because the hint is wrong
 	return QDEL_HINT_QUEUE

code/modules/turbolift/turbolift.dm

@@ -97,6 +97,8 @@
 			if(istype(AM, /mob/living))
 				var/mob/living/M = AM
 				M.gib()
+			else if(istype(AM, /mob/zshadow))
+				AM.Destroy()		//prevent deleting shadow without deleting shadow's shadows
 			else if(AM.simulated && !(istype(AM, /mob/observer)))
 				qdel(AM)