S allius/issue397 (#405)

* add Dashboards log handler to all known loggers

* add list of last 3 warnings/errors to page

* add note list to page

* create LogHandler for the dashboard

- simple memory log handler which stores the last
  64 warnings/errors for the dashboard

* render warnings/errors as note list

* add page for warnings and errors

* fix double defined build target

* add well done message if no errors in the logs

* translate page titles

* more translations

* add Notes page and table for important messages

* add unit tests

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

@@ -1,6 +1,6 @@
 {% extends 'base.html.j2' %}
 
-{% block title %} TSUN Proxy - Connections {% endblock title%}
+{% block title %}{{_("TSUN Proxy - Connections")}}{% endblock title %}
 {% block menu1_class %}w3-blue{% endblock %}
 {% block headline %}<i class="fa fa-network-wired"></i>  {{_('Proxy Connection Overview')}}{% endblock headline %}