Simplified plugin registration and improved registration checks

Change-Id: I60486be70091a5bdc6c2703c73fe6adb52514f32
diff --git a/dev/demo/plugin-server.html b/dev/demo/plugin-server.html
index d91b9e2..15a69d2 100644
--- a/dev/demo/plugin-server.html
+++ b/dev/demo/plugin-server.html
@@ -15,7 +15,7 @@
       <div id="search">
         <ol>
           <li class="active">
-            <div id="container"></div>
+            <div id="match"></div>
             <div id="buttons"></div>
           </li>
         </ol>
diff --git a/dev/demo/plugin-serverdemo.js b/dev/demo/plugin-serverdemo.js
index a6ba4a2..92c4611 100644
--- a/dev/demo/plugin-serverdemo.js
+++ b/dev/demo/plugin-serverdemo.js
@@ -15,12 +15,11 @@
       'desc' : 'Some content about cats',
       // 'about' : 'https://localhost:5678/',
       'embed' : [{
-        'buttonGroup' : 'match',
+        'panel' : 'match',
         'title' : 'Translate',
         'classes' : ['translate'],
         'onClick' : {
           'action' : 'addWidget',
-          'panel' : 'container',
           'template' : 'http://localhost:3003/demo/plugin-client.html',
         }
       }]