removes add_gas() and assert_gas(). next up: do further testing with garbage_collect() present and not present

code/game/turfs/change_turf.dm

@@ -297,7 +297,6 @@ GLOBAL_LIST_INIT(blacklisted_automated_baseturfs, typecacheof(list(
 			continue
 		var/list/S_gases = S.air.gases
 		for(var/id in S_gases)
-			ASSERT_GAS(id, total)
 			total_gases[id] += S_gases[id]
 		total.temperature += S.air.temperature
 

code/game/turfs/open.dm

@@ -292,6 +292,5 @@
 		pulse_strength = min(pulse_strength,air.gases[/datum/gas/carbon_dioxide]*1000,air.gases[/datum/gas/oxygen]*2000) //Ensures matter is conserved properly
 		air.gases[/datum/gas/carbon_dioxide]=max(air.gases[/datum/gas/carbon_dioxide]-(pulse_strength/1000),0)
 		air.gases[/datum/gas/oxygen]=max(air.gases[/datum/gas/oxygen]-(pulse_strength/2000),0)
-		air.assert_gas(/datum/gas/pluoxium)
 		air.gases[/datum/gas/pluoxium]+=(pulse_strength/4000)
 		air.garbage_collect()