TT#80301 Add 'Switch to NEW admin panel' link on Perl based ngcp-panel

Change-Id: I5def9650a94b4dc5ee43c5282016dc5197e0ea4f

etc/ngcp_panel.conf

@@ -12,6 +12,7 @@ log4perl.appender.Default.layout.ConversionPattern=%d{ISO8601} [%p] [%F +%L] %m{
 
 <general>
     maintenance_mode 0
+    ui_enable 0
 </general>
 
 <api_debug_opts>

share/layout/body.tt

@@ -122,6 +122,11 @@
                 [% END; -%]
                 © 2013 - [% date.format(date.now, '%Y') -%] <a href="http://www.sipwise.com">Sipwise GmbH</a>, [% c.loc('all rights reserved') %].
             </div>
+            [% IF c.config.general.ui_enable -%]
+              <div class="nav pull-right">
+                <b><a href="/v2/#/[% c.req.path -%]">[% c.loc('GO TO NEW ADMIN PANEL') -%]</a></b>
+              </div>
+            [% END -%]
         </div>
     </div>
 </div>