Add canonical link and clean alternative link in WUI, related to Alfa…

…nous-team#406 SEO issue

* Add canonical link to HTML header with only 'query' as parameter
* Remove the tailing '?' from alternative link in HTML header for empty requests

src/alfanous-django/templates/base.html

@@ -55,14 +55,14 @@
 
 	<link rel="icon" href="/static/shared/img/icon/icon_32_a.png" sizes="32x32">
 	<link rel="shortcut icon" href="/static/shared/img/icon/icon_16_a.png">
-
-	<link rel="alternate" href="http://www.alfanous.org/{{ current.unit }}/?{{ current.request }}" hreflang="x-default" />
+
+	<link rel="canonical" href="http://www.alfanous.org/{{ LANGUAGE_CODE }}/{{ current.unit }}/{% if params.query %}?query={{ params.query }}{% endif %}" />
+	<link rel="alternate" href="http://www.alfanous.org/{{ current.unit }}/{% if current.request %}?{{ current.request }}{% endif %}" hreflang="x-default" />
     {% for lang_code, lang_name in LANGUAGES %}
                                 {% language lang_code %}
-
-    <link rel="alternate" href="http://www.alfanous.org{% url 'wui.views.results' current.unit  %}?{{ current.request }}" hreflang="{{ lang_code }}" />
+	<link rel="alternate" href="http://www.alfanous.org{% url 'wui.views.results' current.unit  %}{% if current.request %}?{{ current.request }}{% endif %}" hreflang="{{ lang_code }}" />
                                 {% endlanguage %}
-   {% endfor %}
+    {% endfor %}
 
 	<link rel="search" type="application/opensearchdescription+xml" title="Alfanous" href="/static/alfanous-opensearch.xml"/>