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/modules/projectiles/ammunition.dm

@@ -18,7 +18,7 @@
 			BB = new projectile_type(src)
 		pixel_x = rand(-10.0, 10)
 		pixel_y = rand(-10.0, 10)
-		dir = pick(cardinal)
+		set_dir(pick(cardinal))
 
 
 /obj/item/ammo_casing/attackby(obj/item/weapon/W as obj, mob/user as mob)

code/modules/projectiles/targeting.dm

@@ -48,7 +48,7 @@
 	//Lets not spam it.
 	if(lock_time > world.time - 2) return
 	
-	user.dir = get_cardinal_dir(src, A)
+	user.set_dir(get_cardinal_dir(src, A))
 	if(isliving(A) && !(A in target))
 		Aim(A) 	//Clicked a mob, aim at them
 		return 1
@@ -103,7 +103,7 @@
 	else
 		click_empty(M)
 
-	usr.dir = get_cardinal_dir(src, T)
+	usr.set_dir(get_cardinal_dir(src, T))
 
 	if (!firerate) // If firerate is set to lower aim after one shot, untarget the target
 		T.NotTargeted(src)