update elements and fix some bugs

lib/src/neon-animation/neon-animated-pages.html

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 Copyright (c) 2015 The Polymer Project Authors. All rights reserved.
 This code may only be used under the BSD style license found at http://polymer.github.io/LICENSE.txt
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 <link rel="import" href="../polymer/polymer.html">
 <link rel="import" href="../iron-resizable-behavior/iron-resizable-behavior.html">
 <link rel="import" href="../iron-selector/iron-selectable.html">
 <link rel="import" href="neon-animation-runner-behavior.html">
 <link rel="import" href="animations/opaque-animation.html">
 
 <!--
+Material design: [Meaningful transitions](https://www.google.com/design/spec/animation/meaningful-transitions.html)
+
 `neon-animated-pages` manages a set of pages and runs an animation when switching between them. Its
 children pages should implement `Polymer.NeonAnimatableBehavior` and define `entry` and `exit`
 animations to be run when switching to or switching out of the page.
 
 @group Neon Elements
 @element neon-animated-pages
 @demo demo/index.html
 -->
 
 <dom-module id="neon-animated-pages">
@@ skipping 100 matching lines @@
       }
 
       // configure oldPage animations iff exists.
       if (oldPage) {
 
         // cancel the currently running animation if one is ongoing.
         if (oldPage.classList.contains('neon-animating')) {
           this._squelchNextFinishEvent = true;
           this.cancelAnimation();
           this._completeSelectedChanged();
+          this._squelchNextFinishEvent = false;
         }
 
         // configure the animation.
         if (this.exitAnimation) {
           this.animationConfig.push({
             name: this.exitAnimation,
             node: oldPage
           });
         } else {
           if (oldPage.getAnimationConfig) {
@@ skipping 68 matching lines @@
       this.resizerShouldNotify = function(element) {
         return element == selectedPage;
       }
       this.notifyResize();
     }
 
   })
 
 })();
 </script>