round 1 of animation + transition rewrite, while combing Xaric's Tween port

src/Layer.js

@@ -14,8 +14,6 @@ Kinetic.Layer = function(config) {
     this.canvas = document.createElement('canvas');
     this.context = this.canvas.getContext('2d');
     this.canvas.style.position = 'absolute';
-    this.transitions = [];
-    this.transitionIdCounter = 0;
 
     // call super constructors
     Kinetic.Container.apply(this, []);