Added an inline script to detect installation as a plugin.

Script sniffs for "/_plugin/" in location.href. If found it will
automatically populate the REST endpoint and simulate clicking
the "Connect" button.

index.html

@@ -129,5 +129,14 @@
         <div class="twelvecol last"/>
     </div>
 </div>
+<script type="text/javascript">
+$(function() {
+  var l = location, h = l.href, p = l.pathname;
+  if (h.indexOf("/_plugin/") != -1) {
+    document.forms[0].restEndPoint.value = h.substr(0, h.length-p.length);
+    $("#connectButton").click();
+  }
+});
+</script>
 </body>
 </html>