Moves the is_frozen var to a secondary flag

One less var on ALL OBJECTS.

code/game/objects/objs.dm

@@ -24,7 +24,6 @@
 	var/force_blueprints = FALSE //forces the obj to be on the blueprints, regardless of when it was created.
 
 	var/persistence_replacement = null //have something WAY too amazing to live to the next round? Set a new path here. Overuse of this var will make me upset.
-	var/is_frozen = FALSE
 	var/unique_rename = 0 // can you customize the description/name of the thing?
 
 
@@ -47,8 +46,8 @@
 
 /obj/throw_at(atom/target, range, speed, mob/thrower, spin=1, diagonals_first = 0, datum/callback/callback)
 	..()
-	if(is_frozen)
-		visible_message("<span class = 'danger'><b>[src] shatters into a million pieces!</b></span>")
+	if(HAS_SECONDARY_FLAG(src, FROZEN))
+		visible_message("<span class='danger'>[src] shatters into a million pieces!</span>")
 		qdel(src)
 
 /obj/assume_air(datum/gas_mixture/giver)
@@ -225,4 +224,4 @@
 		M << "You have successfully changed \the [name]'s description."
 		return
 	else
-		return
+		return

code/game/turfs/open.dm

@@ -111,7 +111,7 @@
 
 /turf/open/freon_gas_act()
 	for(var/obj/I in contents)
-		if(!I.is_frozen) //let it go
+		if(!HAS_SECONDARY_FLAG(I, FROZEN)) //let it go
 			I.make_frozen_visual()
 	for(var/mob/living/L in contents)
 		if(L.bodytemperature >= 10)
@@ -225,7 +225,7 @@
 		wet_time = MAXIMUM_WET_TIME
 	if(wet == TURF_WET_ICE && air.temperature > T0C)
 		for(var/obj/O in contents)
-			if(O.is_frozen)
+			if(HAS_SECONDARY_FLAG(O, FROZEN))
 				O.make_unfrozen()
 		MakeDry(TURF_WET_ICE)
 		MakeSlippery(TURF_WET_WATER)

code/game/turfs/turf.dm

@@ -175,7 +175,7 @@
 	//melting
 	if(isobj(AM) && air && air.temperature > T0C)
 		var/obj/O = AM
-		if(O.is_frozen)
+		if(HAS_SECONDARY_FLAG(O, FROZEN))
 			O.make_unfrozen()
 
 /turf/proc/is_plasteel_floor()
@@ -476,4 +476,4 @@
 /turf/proc/remove_decal(group)
 	LAZYINITLIST(decals)
 	cut_overlay(decals[group])
-	decals[group] = null
+	decals[group] = null