Issue 2101 - Avoid duplicate interface page strings.

includes/interface.tmpl

 {#
  # This file is part of the Adblock Plus website,
  # Copyright (C) 2006-2015 Eyeo GmbH
  #
  # Adblock Plus is free software: you can redistribute it and/or modify
  # it under the terms of the GNU General Public License version 3 as
  # published by the Free Software Foundation.
  #
  # Adblock Plus is distributed in the hope that it will be useful,
  # but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 10 matching lines @@
       {{ return_type -}}
     </a>
   {% else %}
     {{ return_type }}
   {% endif %}
 {% endmacro %}
 
 {% macro display_interface(interface, links) %}
   {% set interface=interface|parse_interface %}
 
-  <h2>{{ "toc_header"|translate }}</h2>
+  <h2>{{ "toc_header"|translate("interface") }}</h2>
   <ul>
     {% for property in interface %}
       {% if property.type == "method" %}
         <li>
           {{ return_type(property.return_type) }}
           <a href="#method_{{ property.name }}" class="methodname">{{ property.name }}</a>
           (
           {% for argument in property.arguments %}
             {{ argument.type }} {{argument.name }}
             {%- if not loop.last %},{% endif %}
@@ skipping 44 matching lines @@
       </dl>
     {% else %}
       <p id="prop_{{ property.name }}">
         {{ property.modifier }} {{ property.type }}
         <span class="propname">{{ property.name }}</span>
       </p>
       {{ property.description() }}
     {% endif %}
   {% endfor %}
 {% endmacro %}