Move app.js to jquery.zuul.js to indicate a plugin

Tidy up the status page javascript some more.

Change-Id: I1895c74f73e92bcacde132b71ec5798e8307db01

etc/status/public_html/index.html

@@ -43,7 +43,7 @@ under the License.
     <script src="jquery.min.js"></script>
     <script src="jquery-visibility.min.js"></script>
     <script src="jquery.graphite.js"></script>
-    <script src="app.js"></script>
+    <script src="jquery.zuul.js"></script>
     <script>
         (function ($) {
             // Load immediately