Implement OAuth2 service provider functionality.

web/templates/channel.html

@@ -49,6 +49,7 @@
   <div id="access_history_modal"></div>
   <div id="activity_log_modal"></div>
   <div id="removed_from_channel_modal"></div>
+  <div id="register_app_modal"></div>
 <script>
   window.setup_channel_page({{ .Props }});
   $('body').tooltip( {selector: '[data-toggle=tooltip]'} );