Rename mdv -> template_binding, remove experiemntal apis from dart:html

pkg/template_binding/lib/src/element.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-part of mdv;
+part of template_binding;
 
 /** Extensions to the [Element] API. */
-class _ElementExtension extends _NodeExtension {
-  _ElementExtension(Element node) : super(node);
+class _ElementExtension extends NodeBindExtension {
+  _ElementExtension(Element node) : super._(node);
 
   // TODO(jmesserly): should path be optional, and default to empty path?
   // It is used that way in at least one path in JS TemplateElement tests
   // (see "BindImperative" test in original JS code).
   NodeBinding createBinding(String name, model, String path) =>
-      new _AttributeBinding(node, name, model, path);
-
-  // Normally we issue this error in Element._ensureTemplate, but we
-  // avoid calling that from the model getter, so issue the error here.
-  get model => throw new UnsupportedError('$node is not a template.');
+      new _AttributeBinding(_node, name, model, path);
 }
 
 class _AttributeBinding extends NodeBinding {
   final bool conditional;
 
   _AttributeBinding._(node, name, model, path, this.conditional)
       : super(node, name, model, path);
 
   factory _AttributeBinding(Element node, name, model, path) {
     bool conditional = name.endsWith('?');
     if (conditional) {
-      node.xtag.attributes.remove(name);
+      node.attributes.remove(name);
       name = name.substring(0, name.length - 1);
     }
     return new _AttributeBinding._(node, name, model, path, conditional);
   }
 
   Element get node => super.node;
 
   void boundValueChanged(value) {
     if (conditional) {
       if (_toBoolean(value)) {
-        node.xtag.attributes[property] = '';
+        node.attributes[property] = '';
       } else {
-        node.xtag.attributes.remove(property);
+        node.attributes.remove(property);
       }
     } else {
       // TODO(jmesserly): escape value if needed to protect against XSS.
       // See https://github.com/polymer-project/mdv/issues/58
-      node.xtag.attributes[property] = sanitizeBoundValue(value);
+      node.attributes[property] = sanitizeBoundValue(value);
     }
   }
 }