Bug + HTML corrections

Add alt for favicon
Correct datetime format
Remove pubdate (not in html5 spec)
Don't use pretty_url for web.archive.org.

searx/templates/oscar/result_templates/default.html

@@ -1,9 +1,9 @@
 {% from 'oscar/macros.html' import icon %}
 
-<h4 class="result_header">{% if result['favicon'] %}<img width="32" height="32" class="favicon" src="static/{{ theme }}/img/icons/{{ result['favicon'] }}.png" /> {% endif %}<a href="{{ result.url }}">{{ result.title|safe }}</a></h4>
+<h4 class="result_header">{% if result['favicon'] %}<img width="32" height="32" class="favicon" src="static/{{ theme }}/img/icons/{{ result['favicon'] }}.png" alt="{{ result['favicon'] }}" /> {% endif %}<a href="{{ result.url }}">{{ result.title|safe }}</a></h4>
 
-{% if result.publishedDate %}<time class="text-muted" datetime="{{ result.publishedDate }}" pubdate>{{ result.publishedDate }}</time>{% endif %}
-<small><a class="text-info" href="https://web.archive.org/web/{{ result.pretty_url }}">{{ icon('link') }} {{ _('cached') }}</a></small>
+{% if result.publishedDate %}<time class="text-muted" datetime="{{ result.pubdate }}" >{{ result.publishedDate }}</time>{% endif %}
+<small><a class="text-info" href="https://web.archive.org/web/{{ result.url }}">{{ icon('link') }} {{ _('cached') }}</a></small>
 
 {% if result.content %}<p class="result-content">{{ result.content|safe }}</p>{% endif %}