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/pages.py

@@ -7,10 +7,17 @@ from . import web
 @web.route('/')
 async def index():
     return await render_template(
-        'index.html.j2',
-        fetch_url=url_for('web.data_fetch'))
+        'page_index.html.j2',
+        fetch_url=url_for('.data_fetch'))
 
 
 @web.route('/page')
 async def empty():
     return await render_template('empty.html.j2')
+
+
+@web.route('/logging')
+async def logging():
+    return await render_template(
+        'page_logging.html.j2',
+        fetch_url=url_for('.file_fetch'))