516 Renderer update (#20579)

Updated the renderers to work with BYOND 516.
Some update of ZAS to hopefully be more efficient, and cold/hot air
effects.
Gas effects are now less prominent.

Ported from Bay

code/modules/mob/login.dm

@@ -100,7 +100,7 @@
 	clear_important_client_contents(client)
 	enable_client_mobs_in_contents(client)
 
-	CreateRenderers()
+	AddDefaultRenderers()
 	update_client_color()
 	add_click_catcher()
 

code/modules/mob/logout.dm

@@ -10,7 +10,7 @@
 	disconnect_time = world.realtime
 	log_access("Logout: [key_name(src)]")
 	SSstatistics.update_status()
-	RemoveRenderers()
+	ClearRenderers()
 	if(client)
 		clear_important_client_contents(client)