added control sidebar #10 (#87)

- added configurable sidebar #10
- added language switch in sidebar preferences tab #10
- added sidebar tab with kimai beta-info message #10
- use trait for repositories
- improved README

templates/base.html.twig

@@ -57,16 +57,6 @@
     {% if app.user is not null and is_granted('IS_AUTHENTICATED_FULLY') %}
         {{ render(controller('App\\Controller\\ActivityController::recentActivitiesAction')) }}
     {% endif %}
-    {#
-    <li class="dropdown">
-        <a href="#" class="dropdown-toggle" data-toggle="dropdown" role="button" aria-expanded="false"><i class="fa fa-globe"></i> <span class="caret"></span></a>
-        <ul class="dropdown-menu locales" role="menu">
-            {% for locale in locales() %}
-                <li {% if app.request.locale == locale.code %}class="active"{% endif %}><a href="{{ path(app.request.get('_route', 'homepage'), app.request.get('_route_params', [])|merge({ _locale: locale.code })) }}">{{ locale.name|capitalize }}</a></li>
-            {% endfor %}
-        </ul>
-    </li>
-    #}
 {% endblock %}
 
 {% block avanzu_navbar_toggle %}{{ parent() }}{% endblock %}