fix(entities): use Mask interface properly

Author: Valentin Vetter

engine/modules/entities/src/main/java/com/codingame/gameengine/module/entities/Entity.java

@@ -449,29 +449,18 @@ public boolean isVisible() {
         return visible;
     }
 
-    /**
-     * Sets a given <code>Shape</code> as this <code>Entity</code>'s <code>Mask</code>.
-     * 
-     * @param shape
-     *            the mask.
-     * @return this <code>Entity</code>.
-     */
-    public T setMask(Shape<?> shape) {
-        return saveMask(shape);
-    }
-
     /**
      * <p>
-     * Sets a given <code>Sprite</code> as this <code>Entity</code>'s <code>Mask</code>.
+     * Sets a given <code>Mask</code> as this <code>Entity</code>'s <code>Mask</code>.
      * </p>
      * <b>Note:</b> texture masks will only work on browsers which support WebGL
      * 
      * @param sprite
      *            the mask.
      * @return this <code>Entity</code>.
      */
-    public T setMask(Sprite sprite) {
-        return saveMask(sprite);
+    public T setMask(Mask mask) {
+        return saveMask(mask);
     }
 
     /**