[enh] prettier search url display

searx/templates/courgette/results.html

     <div id="sidebar">
         <div id="search_url">
             {{ _('Search URL') }}:
-            <input type="text" value="{{ base_url }}?q={{ q|urlencode }}&amp;pageno={{ pageno }}{% if selected_categories %}&amp;category_{{ selected_categories|join("&category_")|replace(' ','+') }}{% endif %}" readonly />
+            <input type="text" value="{{ base_url }}?q={{ q|urlencode }}{% if selected_categories %}&amp;categories={{ selected_categories|join(",") | replace(' ','+') }}{% endif %}{% if pageno > 1 %}&amp;pageno={{ pageno }}{% endif %}" readonly />
         </div>
         <div id="apis">
             {{ _('Download results') }}<br />
     </div>
     {% endif %}
 </div>
-{% endblock %}
+{% endblock %}

searx/templates/default/results.html

 
         <div id="search_url">
             {{ _('Search URL') }}:
-            <input type="text" value="{{ base_url }}?q={{ q|urlencode }}&amp;pageno={{ pageno }}{% if selected_categories %}&amp;category_{{ selected_categories|join("&category_")|replace(' ','+') }}{% endif %}" readonly />
+            <input type="text" value="{{ base_url }}?q={{ q|urlencode }}{% if selected_categories %}&amp;categories={{ selected_categories|join(",") | replace(' ','+') }}{% endif %}{% if pageno > 1 %}&amp;pageno={{ pageno }}{% endif %}" readonly />
         </div>
         <div id="apis">
         {{ _('Download results') }}

searx/templates/oscar/results.html

                     <form role="form">
                         <div class="form-group">
                             <label for="search_url">{{ _('Search URL') }}</label>
-                            <input id="search_url" type="url" class="form-control select-all-on-click cursor-text" name="search_url" value="{{ base_url }}?q={{ q|urlencode }}&amp;pageno={{ pageno }}{% if selected_categories %}&amp;category_{{ selected_categories|join("&category_")|replace(' ','+') }}{% endif %}" readonly>
+                            <input id="search_url" type="url" class="form-control select-all-on-click cursor-text" name="search_url" value="{{ base_url }}?q={{ q|urlencode }}{% if selected_categories %}&amp;categories={{ selected_categories|join(",") | replace(' ','+') }}{% endif %}{% if pageno > 1 %}&amp;pageno={{ pageno }}{% endif %}" readonly>
                         </div>
                     </form>