re-integrated simple serialization and deserialization with new attrs structure

src/Layer.js

@@ -11,6 +11,7 @@
  */
 Kinetic.Layer = function(config) {
     this.nodeType = 'Layer';
+    
     this.canvas = document.createElement('canvas');
     this.context = this.canvas.getContext('2d');
     this.canvas.style.position = 'absolute';