MT#20797 additional configurable documentation links

format is

  <external_documentation>
    <link>
      name Google
      url  http://elgoog.im/
    </link>
    <link>
      name Sipwise Website
      url  https://sipwise.com/
    </link>
  </external_documentation>

Change-Id: Id9283f1df5fb5933fa6523cbf2f01a458fa21475

lib/NGCP/Panel/Controller/Root.pm

@@ -214,6 +214,10 @@ sub auto :Private {
         $c->detach('/denied_page');
     }
 
+    if (exists $c->config->{external_documentation}{link} && 'ARRAY' ne ref $c->config->{external_documentation}{link}) {
+        $c->config->{external_documentation}{link} = [$c->config->{external_documentation}{link}];
+    }
+
     # load top menu widgets
     my $topmenu_templates = [];
     if ($c->user->roles eq 'admin') {

ngcp_panel.conf

@@ -379,3 +379,6 @@ log4perl.appender.Default.layout.ConversionPattern=%d{ISO8601} [%p] [%F +%L] %m{
     key iBmTdavJ8joPW3HO
     iv tww21lQe6cmywrp3
 </vouchers>
+
+<external_documentation>
+</external_documentation>

share/templates/widgets/admin_topmenu_settings.tt

@@ -5,8 +5,11 @@
         <b class="caret"></b>
     </a>
     <ul class="dropdown-menu">
-        <li><a href="[% c.uri_for('/api/') %]">[% c.loc('API') %]</a></li>
-        <li><a href="[% c.uri_for('/handbook/') %]">[% c.loc('Handbook') %]</a></li>
+        <li><a href="[% c.uri_for('/api/') %]" class="ngcp-noback-link">[% c.loc('API') %]</a></li>
+        <li><a href="[% c.uri_for('/handbook/') %]" class="ngcp-noback-link">[% c.loc('Handbook') %]</a></li>
+        [% FOR l IN c.config.external_documentation.link -%]
+            <li><a href="[% l.url %]" class="ngcp-noback-link">[% l.name | html %]</a></li>
+        [% END; -%]
     </ul>
 </li>
 <li class="dropdown">