Improve automatic emails with temporary urls

This MR targets the improvement for automatic emails concerning validation of new users by supervisors/re-validation of users.

Fixes #542 (closed)

Fixes #550 (closed)

beat/web/accounts/templates/accounts/url_rejection.html

+{% extends "base.html" %}
+{% comment %}
+ * Copyright (c) 2020 Idiap Research Institute, http://www.idiap.ch/
+ * Contact: beat.support@idiap.ch
+ *
+ * This file is part of the beat.web module of the BEAT platform.
+ *
+ * Commercial License Usage
+ * Licensees holding valid commercial BEAT licenses may use this file in
+ * accordance with the terms contained in a written agreement between you
+ * and Idiap. For further information contact tto@idiap.ch
+ *
+ * Alternatively, this file may be used under the terms of the GNU Affero
+ * Public License version 3 as published by the Free Software and appearing
+ * in the file LICENSE.AGPL included in the packaging of this file.
+ * The BEAT platform is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * You should have received a copy of the GNU Affero Public License along
+ * with the BEAT platform. If not, see http://www.gnu.org/licenses/.
+{% endcomment %}
+
+{% load fingerprint %}
+{% load ui_tags %}
+{% load gravatar %}
+{% load registration_tags %}
+{% load account_tags %}
+
+{% block title %}As requested, the supervision from {{supervisiontrack.supervisor.username}} for {{supervisiontrack.supervisee.username}} is revoked!{% endblock %}
+
+{% block stylesheets %}
+{{ block.super }}
+<link rel="stylesheet" href="{% fingerprint "accounts/css/dialogs.css" %}" type="text/css" media="screen" />
+<link rel="stylesheet" href="{% fingerprint "jquery-ui/themes/base/minified/jquery-ui.min.css" %}" type="text/css" media="screen" />
+<link href="{% fingerprint "/bootstrap-toggle/css/bootstrap-toggle.min.css" %}" rel="stylesheet">
+<link rel="stylesheet" href="{% fingerprint "datatables/media/css/dataTables.bootstrap.min.css" %}" type="text/css" media="screen" />
+{% endblock %}
+
+{% block scripts %}
+{{ block.super }}
+{% csrf_token %}
+
+<script src="{% fingerprint "bootstrap3-typeahead/bootstrap3-typeahead.min.js" %}" type="text/javascript" charset="utf-8"></script>
+<script src="{% fingerprint "accounts/js/dialogs.js" %}" type="text/javascript" charset="utf-8"></script>
+<script src="{% fingerprint "jquery-ui/ui/minified/jquery.ui.core.min.js" %}" type="text/javascript" charset="utf-8"></script>
+<script src="{% fingerprint "jquery-ui/ui/minified/jquery.ui.position.min.js" %}" type="text/javascript" charset="utf-8"></script>
+<script src="{% fingerprint "jquery-ui/ui/minified/jquery.ui.widget.min.js" %}" type="text/javascript" charset="utf-8"></script>
+<script src="{% fingerprint "jquery-ui/ui/minified/jquery.ui.button.min.js" %}" type="text/javascript" charset="utf-8"></script>
+<script src="{% fingerprint "jquery-ui/ui/minified/jquery.ui.dialog.min.js" %}" type="text/javascript" charset="utf-8"></script>
+<script src="https://gitcdn.github.io/bootstrap-toggle/2.2.2/js/bootstrap-toggle.min.js"></script>
+{% endblock %}
+
+{% block content %}
+<div class="row">
+  <div class="col-sm-6 col-sm-offset-3">
+    {% with 48 as width %}
+	<h3 class="page-title"><img class="img-circle" width="{{ width }}" height="{{ width }}" data-toggle="tooltip" data-placement="top" title="To change your avatar, visit http://gravatar.com"></img> As requested, the supervision from {{supervisiontrack.supervisor.username}} for {{supervisiontrack.supervisee.username}} is revoked!</h3>
+    {% endwith %}
+  </div>
+</div>
+
+
+{% endblock %}