update elements and fix some bugs

lib/src/iron-icon/iron-icon.html

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 @license
 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
 The complete set of authors may be found at http://polymer.github.io/AUTHORS.txt
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@@ skipping 34 matching lines @@
     <link rel="import" href="/components/iron-icons/communication-icons.html">
 
     <iron-icon icon="communication:email"></iron-icon>
 
 You can also create custom icon sets of bitmap or SVG icons.
 
 Example of using an icon named `cherry` from a custom iconset with the ID `fruit`:
 
     <iron-icon icon="fruit:cherry"></iron-icon>
 
-See [iron-iconset](#iron-iconset) and [iron-iconset-svg](#iron-iconset-svg) for more information about
+See [iron-iconset](iron-iconset) and [iron-iconset-svg](iron-iconset-svg) for more information about
 how to create a custom iconset.
 
-See [iron-icons](https://elements.polymer-project.org/elements/iron-icons?view=demo:demo/index.html) for the default set of icons.
+See the [iron-icons demo](iron-icons?view=demo:demo/index.html) to see the icons available
+in the various iconsets.
 
 
 ### Styling
 
 The following custom properties are available for styling:
 
 Custom property | Description | Default
 ----------------|-------------|----------
 `--iron-icon-width` | Width of the icon | `24px`
 `--iron-icon-height` | Height of the icon | `24px`
+`--iron-icon-fill-color` | Fill color of the svg icon | `currentcolor`
+`--iron-icon-stroke-color` | Stroke color of the svg icon | none
 
 @group Iron Elements
 @element iron-icon
 @demo demo/index.html
 @hero hero.svg
 @homepage polymer.github.io
 -->
 
 <dom-module id="iron-icon">
 
   <style>
     :host {
       @apply(--layout-inline);
       @apply(--layout-center-center);
       position: relative;
 
       vertical-align: middle;
 
-      fill: currentcolor;
+      fill: var(--iron-icon-fill-color, currentcolor);
+      stroke: var(--iron-icon-stroke-color, none);
 
       width: var(--iron-icon-width, 24px);
       height: var(--iron-icon-height, 24px);
     }
   </style>
 
   <template>
   </template>
 
   <script>
@@ skipping 24 matching lines @@
 
         /**
          * If using iron-icon without an iconset, you can set the src to be
          * the URL of an individual icon image file. Note that this will take
          * precedence over a given icon attribute.
          */
         src: {
           type: String,
           observer: '_srcChanged'
         },
-        
+
+        /**
+         * @type {!Polymer.IronMeta}
+         */
         _meta: {
           value: Polymer.Base.create('iron-meta', {type: 'iconset'})
         }
-        
+
       },
 
       _DEFAULT_ICONSET: 'icons',
 
       _iconChanged: function(icon) {
         var parts = (icon || '').split(':');
         this._iconName = parts.pop();
         this._iconsetName = parts.pop() || this._DEFAULT_ICONSET;
         this._updateIcon();
       },
 
       _srcChanged: function(src) {
         this._updateIcon();
       },
 
       _usesIconset: function() {
         return this.icon || !this.src;
       },
 
       /** @suppress {visibility} */
       _updateIcon: function() {
         if (this._usesIconset()) {
           if (this._iconsetName) {
-            this._iconset = this._meta.byKey(this._iconsetName);
+            this._iconset = /** @type {?Polymer.Iconset} */ (
+              this._meta.byKey(this._iconsetName));
             if (this._iconset) {
               this._iconset.applyIcon(this, this._iconName, this.theme);
+              this.unlisten(window, 'iron-iconset-added', '_updateIcon');
             } else {
-              this._warn(this._logf('_updateIcon', 'could not find iconset `'
-                + this._iconsetName + '`, did you import the iconset?'));
+              this.listen(window, 'iron-iconset-added', '_updateIcon');
             }
           }
         } else {
           if (!this._img) {
             this._img = document.createElement('img');
             this._img.style.width = '100%';
             this._img.style.height = '100%';
             this._img.draggable = false;
           }
           this._img.src = this.src;
           Polymer.dom(this.root).appendChild(this._img);
         }
       }
 
     });
 
   </script>
 
 </dom-module>