Changes in webui to comply with the safe html changes. Now that Nodes can be

lib/safe_html.dart

Index: lib/safe_html.dart
diff --git a/lib/safe_html.dart b/lib/safe_html.dart
index 33854719453ffd7c485816e85359ad11b956cbd4..a80b28a81beed854fbbf32e7b7611bbc0a5367bb 100644
--- a/lib/safe_html.dart
+++ b/lib/safe_html.dart
@@ -6,13 +6,20 @@
 // dart:html?
 library safe_html;
 
+import 'package:meta/meta.dart';
+
 /** Declares a string that is a well-formed HTML fragment. */
+// TODO(sigmund): delete this type now that Element.html is safe by default.
 class SafeHtml {
 
   /** Underlying html string. */
   String _html;
 
-  // TODO(sigmund): provide a constructor that does html validation
+  /**
+   * dart:html now supports sanitizing elements. You can add any node
+   * directly in your bindings instead of creating instances of SafeHtml.
+   */
+  @deprecated
   SafeHtml.unsafe(this._html);
 
   String toString() => _html;