add change pwd|lang|theme; twig-ify standard_error()

Signed-off-by: Michael Kaufmann <d00p@froxlor.org>

templates/Froxlor/misc/alert.html.twig

@@ -0,0 +1,25 @@
+{% extends "Froxlor/userarea.html.twig" %}
+
+{% set body_class = "min-vh-100 d-flex align-items-center" %}
+
+{% block content %}
+<div class="alert alert-{{ type }} fade show" role="alert">
+	<h4 class="alert-heading">
+		{{ heading }}
+	</h4>
+	<p>
+		{{ alert_msg|raw }}
+	</p>
+	{% if alert_info %}
+	<hr>
+	<p class="mb-0">
+	<pre>{{ alert_info|raw }}</pre>
+	</p>
+	{% endif %}
+	{% if redirect_link %}
+	<p class="mt-1">
+		<a href="{{ redirect_link }}" class="btn btn-{{ btntype }}">{% if type == 'danger' %}{{ lng('panel.back') }}{% else %}{{ lng('success.clickheretocontinue') }}{% endif %}</a>
+	</p>
+	{% endif %}
+</div>
+{% endblock %}