Correct handling of spawners depth

gamedata/objects/ingame/spawner.py

@@ -19,6 +19,9 @@ class Spawner(BaseObject):
                 self.skin = random.choice(skins["specials"])
         self.fallsprite = game.sprite_lib["lemmings/"+self.skin+"/falling.png"]
 
+        # Depth updating based on position
+        self.depth = 1+self.rect[1]/100
+
     def step(self):
         if self.timer.tick(self.game.dt):
             lemming = Lemming(self.rect[0],self.rect[1],self.game,speedmargin=self.speedmargin,skin=self.skin)