Replace explicit z-level checks with defines

code/modules/admin/admin.dm

@@ -606,7 +606,7 @@
 /datum/admins/proc/unprison(mob/M in GLOB.mob_list)
 	set category = "Admin"
 	set name = "Unprison"
-	if (M.z == ZLEVEL_CENTCOM)
+	if (is_centcom_level(M.z))
 		SSjob.SendToLateJoin(M)
 		message_admins("[key_name_admin(usr)] has unprisoned [key_name_admin(M)]")
 		log_admin("[key_name(usr)] has unprisoned [key_name(M)]")

code/modules/admin/player_panel.dm

@@ -360,7 +360,7 @@
 					if(isdrone(M))
 						drones++
 						continue
-					if(M.z == ZLEVEL_CENTCOM)
+					if(is_centcom_level(M.z))
 						living_skipped++
 						continue
 					living_players++

code/modules/admin/secrets.dm

@@ -445,7 +445,7 @@
 				return
 			SSblackbox.record_feedback("tally", "admin_secrets_fun_used", 1, "Egalitarian Station")
 			for(var/obj/machinery/door/airlock/W in GLOB.machines)
-				if((W.z in GLOB.station_z_levels) && !istype(get_area(W), /area/bridge) && !istype(get_area(W), /area/crew_quarters) && !istype(get_area(W), /area/security/prison))
+				if(is_station_level(W.z) && !istype(get_area(W), /area/bridge) && !istype(get_area(W), /area/crew_quarters) && !istype(get_area(W), /area/security/prison))
 					W.req_access = list()
 			message_admins("[key_name_admin(usr)] activated Egalitarian Station mode")
 			priority_announce("CentCom airlock control override activated. Please take this time to get acquainted with your coworkers.", null, 'sound/ai/commandreport.ogg')

code/modules/admin/verbs/debug.dm

@@ -521,7 +521,7 @@ GLOBAL_PROTECT(LastAdminCalledProc)
 	for(var/area/A in world)
 		if(on_station)
 			var/turf/picked = safepick(get_area_turfs(A.type))
-			if(picked && (picked.z in GLOB.station_z_levels))
+			if(picked && is_station_level(picked.z))
 				if(!(A.type in areas_all) && !is_type_in_typecache(A, station_areas_blacklist))
 					areas_all.Add(A.type)
 		else if(!(A.type in areas_all))

code/modules/admin/verbs/one_click_antag.dm

@@ -35,7 +35,7 @@
 		return FALSE
 	if(onstation)
 		var/turf/T = get_turf(applicant)
-		if(!(T.z in GLOB.station_z_levels))
+		if(!is_station_level(T.z))
 			return FALSE
 	if(conscious && applicant.stat) //incase you don't care about a certain antag being unconcious when made, ie if they have selfhealing abilities.
 		return FALSE