added clipping functionality to containers. Currently, the clipping function can only be applied to layers and groups. The clipping region is also subject to the containers transforms, which means that you can also create transformed clipping regions.

src/Layer.js

@@ -8,6 +8,7 @@
      * @param {Boolean} [config.clearBeforeDraw] set this property to false if you don't want
      * to clear the canvas before each layer draw.  The default value is true.
      * {{NodeParams}}
+     * {{ContainerParams}}
      */
     Kinetic.Layer = function(config) {
         this._initLayer(config);