update elements and fix some bugs

lib/src/iron-form-element-behavior/iron-form-element-behavior.html

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@@ skipping 35 matching lines @@
       value: {
         notify: true,
         type: String
       },
 
       /**
        * Set to true to mark the input as required. If used in a form, a
        * custom element that uses this behavior should also use
        * Polymer.IronValidatableBehavior and define a custom validation method.
        * Otherwise, a `required` element will always be considered valid.
-       * It's also strongly recomended to provide a visual style for the element
-       * when it's value is invalid.
+       * It's also strongly recommended to provide a visual style for the element
+       * when its value is invalid.
        */
       required: {
         type: Boolean,
         value: false
       },
 
       /**
        * The form that the element is registered to.
        */
       _parentForm: {
         type: Object
       }
     },
 
     attached: function() {
       // Note: the iron-form that this element belongs to will set this
       // element's _parentForm property when handling this event.
       this.fire('iron-form-element-register');
     },
 
     detached: function() {
       if (this._parentForm) {
         this._parentForm.fire('iron-form-element-unregister', {target: this});
       }
     }
 
   };
 
 </script>