POLARIS: Fix several Destroy()s

code/modules/mob/mob_planes.dm

@@ -94,6 +94,9 @@
 	var/invis_toggle = FALSE
 	var/list/sub_planes
 
+/obj/screen/plane_master/New()
+	..(null) //Never be in anything ever.
+
 /obj/screen/plane_master/proc/set_desired_alpha(var/new_alpha)
 	if(new_alpha != alpha && new_alpha > 0 && new_alpha <= 255)
 		desired_alpha = new_alpha

code/modules/nano/modules/nano_module.dm

@@ -5,6 +5,10 @@
 /datum/nano_module/New(var/host)
 	src.host = host
 
+/datum/nano_module/Destroy()
+	host = null
+	return ..()
+
 /datum/nano_module/nano_host()
 	return host ? host : src