Port SSnightshift from Paradise

Makes the station have a night mode.

code/modules/security levels/security levels.dm

@@ -64,10 +64,6 @@
 				else
 					security_announcement_down.Announce("[config.alert_desc_red_downto]", "Attention! Code red!")
 				security_level = SEC_LEVEL_RED
-				/*	- At the time of commit, setting status displays didn't work properly
-				var/obj/machinery/computer/communications/CC = locate(/obj/machinery/computer/communications,world)
-				if(CC)
-					CC.post_status("alert", "redalert")*/
 			if(SEC_LEVEL_DELTA)
 				security_announcement_up.Announce("[config.alert_desc_delta]", "Attention! Delta alert level reached!", new_sound = 'sound/effects/siren.ogg')
 				security_level = SEC_LEVEL_DELTA
@@ -85,6 +81,9 @@
 		else
 			atc.reroute_traffic(yes = 0)
 
+		spawn()
+			SSnightshift.check_nightshift()
+
 
 /proc/get_security_level()
 	switch(security_level)