Fix memory leak in utiLITI editor when moving around light sources

Implemented an editor specific fix that does not cache ambient light images for when the application's name is "utiLITI".

Fixes #3

src/de/gurkenlabs/litiengine/graphics/AmbientLight.java

@@ -81,7 +81,10 @@ public void createImage() {
     g.setComposite(comp);
     g.dispose();
     this.image = img;
-    ImageCache.IMAGES.put(cacheKey, img);
+
+    if (!Game.getInfo().getName().equals("utiLITI")) {
+      ImageCache.IMAGES.put(cacheKey, img);
+    }
   }
 
   public int getAlpha() {