refactor 'dir = ' into 'set_dir()'

This should have little/no gameplay effect right now, just paving the
 way for directional lights.
Replaced handle_rotation() on buckly things with this.

Signed-off-by: Mloc-Argent <colmohici@gmail.com>

code/game/objects/effects/biomass_rift.dm

@@ -30,7 +30,7 @@
 		if(!IsValidBiomassLoc(T))
 			continue
 		var/obj/effect/biomass/starting = new /obj/effect/biomass(T)
-		starting.dir = get_dir(src,starting)
+		starting.set_dir(get_dir(src,starting))
 		starting.originalRift = src
 		linkedBiomass += starting
 		spawn(1) //DEBUG
@@ -53,13 +53,13 @@
 			return
 		switch(dir)
 			if(NORTHWEST)
-				dir = NORTH
+				set_dir(NORTH)
 			if(NORTHEAST)
-				dir = EAST
+				set_dir(EAST)
 			if(SOUTHWEST)
-				dir = WEST
+				set_dir(WEST)
 			if(SOUTHEAST)
-				dir = SOUTH
+				set_dir(SOUTH)
 		sleep(spreadDelay)
 		Spread()
 
@@ -93,7 +93,7 @@
 	var/obj/effect/biomass/newBiomass = new /obj/effect/biomass(get_step(src,direction))
 	newBiomass.curDistance = curDistance + 1
 	newBiomass.maxDistance = maxDistance
-	newBiomass.dir = direction
+	newBiomass.set_dir(direction)
 	newBiomass.originalRift = originalRift
 	newBiomass.icon_state = "[originalRift.newicon]" //DEBUG
 	originalRift.linkedBiomass += newBiomass
@@ -110,7 +110,7 @@
 		if(!IsValidBiomassLoc(T,src))
 			continue
 		var/obj/effect/biomass/starting = new /obj/effect/biomass(T)
-		starting.dir = get_dir(src,starting)
+		starting.set_dir(get_dir(src,starting))
 		starting.maxDistance = maxDistance
 
 /proc/IsValidBiomassLoc(turf/location,obj/effect/biomass/source = null)

code/game/objects/effects/chemsmoke.dm

@@ -192,7 +192,7 @@
 		chemholder.reagents.copy_to(smoke, chemholder.reagents.total_volume / dist, safety = 1)	//copy reagents to the smoke so mob/breathe() can handle inhaling the reagents
 	smoke.icon = I
 	smoke.layer = 6
-	smoke.dir = pick(cardinal)
+	smoke.set_dir(pick(cardinal))
 	smoke.pixel_x = -32 + rand(-8,8)
 	smoke.pixel_y = -32 + rand(-8,8)
 	walk_to(smoke, T)

code/game/objects/effects/decals/Cleanable/fuel.dm

@@ -40,7 +40,7 @@ obj/effect/decal/cleanable/liquid_fuel
 		icon_state = "mustard"
 		anchored = 0
 		New(newLoc, amt = 1, d = 0)
-			dir = d //Setting this direction means you won't get torched by your own flamethrower.
+			set_dir(d) //Setting this direction means you won't get torched by your own flamethrower.
 			. = ..()
 
 		Spread()

code/game/objects/effects/effect_system.dm

@@ -402,7 +402,7 @@ steam.start() -- spawns the effect
 					if(istype(T, /turf/space))
 						var/obj/effect/effect/ion_trails/I = new /obj/effect/effect/ion_trails(src.oldposition)
 						src.oldposition = T
-						I.dir = src.holder.dir
+						I.set_dir(src.holder.dir)
 						flick("ion_fade", I)
 						I.icon_state = "blank"
 						spawn( 20 )
@@ -449,7 +449,7 @@ steam.start() -- spawns the effect
 					var/obj/effect/effect/steam/I = new /obj/effect/effect/steam(src.oldposition)
 					src.number++
 					src.oldposition = get_turf(holder)
-					I.dir = src.holder.dir
+					I.set_dir(src.holder.dir)
 					spawn(10)
 						I.delete()
 						src.number--

code/game/objects/effects/glowshroom.dm

@@ -28,7 +28,7 @@
 
 	..()
 
-	dir = CalcDir()
+	set_dir(CalcDir())
 
 	if(!floor)
 		switch(dir) //offset to make it be on the wall rather than on the floor

code/game/objects/effects/step_triggers.dm

@@ -71,7 +71,7 @@
 				var/predir = AM.dir
 				step(AM, direction)
 				if(!facedir)
-					AM.dir = predir
+					AM.set_dir(predir)