HTML Search: Use sphinx's built in search template file

Instead of using our own template uses sphinx's basic search.html 
instead.
This change is almost identical except for the new search page includes 
a search box. As a result, the search box is hidden on the search page.

sphinx_rtd_theme/search.html

@@ -1,55 +0,0 @@
-{#
-    basic/search.html
-    ~~~~~~~~~~~~~~~~~
-
-    Template for the search page.
-
-    :copyright: Copyright 2007-2013 by the Sphinx team, see AUTHORS.
-    :license: BSD, see https://github.com/sphinx-doc/sphinx/blob/master/LICENSE for details.
-#}
-{%- extends "layout.html" %}
-{% set title = _('Search') %}
-{% set display_vcs_links = False %}
-{%- block scripts %}
-    {{ super() }}
-    <script type="text/javascript" src="{{ pathto('_static/searchtools.js', 1) }}"></script>
-{%- endblock %}
-{% block footer %}
-  <script type="text/javascript">
-    jQuery(function() { Search.loadIndex("{{ pathto('searchindex.js', 1) }}"); });
-  </script>
-  {# this is used when loading the search index using $.ajax fails,
-     such as on Chrome for documents on localhost #}
-  <script type="text/javascript" id="searchindexloader"></script>
-  {{ super() }}
-{% endblock %}
-{% block body %}
-  <noscript>
-  <div id="fallback" class="admonition warning">
-    <p class="last">
-      {% trans trimmed %}Please activate JavaScript to enable the search
-      functionality.{% endtrans %}
-    </p>
-  </div>
-  </noscript>
-
-  {% if search_performed %}
-    {# Translators: Search is a noun, not a verb #}
-    <h2>{{ _('Search Results') }}</h2>
-    {% if not search_results %}
-      <p>{{ _('Your search did not match any documents. Please make sure that all words are spelled correctly and that you\'ve selected enough categories.') }}</p>
-    {% endif %}
-  {% endif %}
-  <div id="search-results">
-  {% if search_results %}
-    <ul>
-    {% for href, caption, context in search_results %}
-      <li>
-        <a href="{{ pathto(item.href) }}">{{ caption }}</a>
-        <p class="context">{{ context|e }}</p>
-      </li>
-    {% endfor %}
-    </ul>
-  {% endif %}
-  </div>
-{% endblock %}

sphinx_rtd_theme/searchbox.html

@@ -1,4 +1,4 @@
-{%- if 'singlehtml' not in builder %}
+{%- if pagename != "search" and 'singlehtml' not in builder %}
 <div role="search">
   <form id="rtd-search-form" class="wy-form" action="{{ pathto('search') }}" method="get">
     <input type="text" name="q" placeholder="{{ _('Search docs') }}" />