[mod] default template modifications

- more smartphone friendly
- more text browser friendly
- next button always on the right
- in case of small screen supporting touch event, categories are displayed on one line with a scroll

searx/templates/default/search.html

@@ -1,6 +1,6 @@
 <form method="{{ method or 'POST' }}" action="{{ url_for('index') }}" id="search_form">
   <div id="search_wrapper">
-    <input type="text" placeholder="{{ _('Search for...') }}" id="q" class="q" name="q" tabindex="1" autocomplete="off" {% if q %}value="{{ q }}"{% endif %}/>
+    <input type="text" placeholder="{{ _('Search for...') }}" id="q" class="q" name="q" tabindex="1" autocomplete="off" size="100" {% if q %}value="{{ q }}"{% endif %}/>
     <input type="submit" value="search" id="search_submit" />
   </div>
   {% include 'default/categories.html' %}