Roll Observatory packages and add a roll script

packages/polymer/example/component/news/web/news-component.html

+<polymer-element name="x-news" extends="ul">
+  <template>
+    <style scoped>
+      div.breaking {
+          color: Red;
+          font-size: 20px;
+          border: 1px dashed Purple;
+      }
+      div.other {
+          padding: 2px 0 0 0;
+          border: 1px solid Cyan;
+      }
+    </style>
+    <div class="breaking">
+      <h2>Breaking Stories</h2>
+      <ul>
+          <content select=".breaking"></content>
+      </ul>
+    </div>
+    <div class="other">
+      <h2>Other News</h2>
+      <ul>
+          <content></content>
+      </ul>
+    </div>
+  </template>
+  <script type="application/dart">
+    import 'dart:html';
+    import 'package:polymer/polymer.dart';
+
+    class XNews extends UListElement with Polymer {
+      XNews.created() : super.created() {
+        polymerCreated();
+      }
+    }
+
+    @initMethod
+    _init() {
+      Polymer.register('x-news', XNews);
+    }
+  </script>
+</polymer-element>