S allius/issue394 (#400)

* store logging path in Config class

* rename template files and page files

* jump to referer page

- after changing the language, we jump to
  the referer page, if the attribute exists

* build and send list of log-files

* rename Download page into Log files

* initialize log-path in test config

* improve dashboard unit tests

 - add log file tests
 - check content-languages after language switch

* initialize config structure for log-file tests

* add test log file to project

* add sub_dir to test log path

- non files must be skipped. To test this we add
  a sub directory to the test log directory

* add german translations

* set quart debug flag for debug versions

* update changelog

app/src/web/templates/base.html.j2

@@ -55,16 +55,16 @@
       </div>
       <div class="w3-bar-block">
         <button href="#" class="w3-bar-item w3-button w3-padding-16 w3-hide-large w3-dark-grey w3-hover-black" onclick="w3_close()" title="close menu"><i class="fa fa-remove fa-fw"></i>  Close Menu</button>
-        <a href="{{ url_for('web.index')}}" class="w3-bar-item w3-button w3-padding {% block menu1_class %}{% endblock %}"><i class="fa fa-network-wired fa-fw"></i>  {{_('Connections')}}</a>
-        <a href="{{ url_for('web.empty')}}" class="w3-bar-item w3-button w3-padding {% block menu2_class %}{% endblock %}"><i class="fa fa-database fa-fw"></i>  MQTT</a>
-        <a href="{{ url_for('web.empty')}}" class="w3-bar-item w3-button w3-padding"><i class="fa fa-file-export fa-fw {% block menu3_class %}{% endblock %}"></i>  Downloads</a>
+        <a href="{{ url_for('.index')}}" class="w3-bar-item w3-button w3-padding {% block menu1_class %}{% endblock %}"><i class="fa fa-network-wired fa-fw"></i>  {{_('Connections')}}</a>
+        <a href="{{ url_for('.empty')}}" class="w3-bar-item w3-button w3-padding {% block menu2_class %}{% endblock %}"><i class="fa fa-database fa-fw"></i>  MQTT</a>
+        <a href="{{ url_for('.logging')}}" class="w3-bar-item w3-button w3-padding {% block menu3_class %}{% endblock %}"><i class="fa fa-file-export fa-fw"></i>  {{_('Log Files')}}</a>
       </div>
     </nav>
   
   
     <!-- Overlay effect when opening sidebar on small screens -->
     <button class="w3-overlay w3-hide-large w3-animate-opacity" onclick="w3_close()" style="cursor:pointer" title="close side menu" id="myOverlay"></button>
-  
+    
     <!-- !PAGE CONTENT! -->
     <div class="w3-main" style="margin-left:250px;margin-top:43px;">