pagekite: Fix regression not showing description

After the recent cleanup, pagekite no longer shows description before
installation.  Only after installation does it show the insturctions
about why it is needed.  Also in the description {box_name} is not
substituted and there are incorrect escape sequences.

Revert this earlier change that causes these regressions.

plinth/modules/pagekite/__init__.py

@@ -20,9 +20,10 @@ Plinth module to configure PageKite
 """
 
 from django.utils.translation import ugettext_lazy as _
-from plinth import cfg
 
 from . import utils
+from plinth import cfg
+from plinth.utils import format_lazy
 
 version = 1
 
@@ -30,6 +31,39 @@ depends = ['system', 'names']
 
 title = _('Public Visibility (PageKite)')
 
+description = [
+    format_lazy(
+        _('PageKite is a system for exposing {box_name} services when '
+          'you don\'t have a direct connection to the Internet. You only '
+          'need this if your {box_name} services are unreachable from '
+          'the rest of the Internet. This includes the following '
+          'situations:'), box_name=_(cfg.box_name)),
+
+    format_lazy(
+        _('{box_name} is behind a restricted firewall.'),
+        box_name=_(cfg.box_name)),
+
+    format_lazy(
+        _('{box_name} is connected to a (wireless) router which you '
+          'don\'t control.'), box_name=_(cfg.box_name)),
+
+    _('Your ISP does not provide you an external IP address and '
+      'instead provides Internet connection through NAT.'),
+
+    _('Your ISP does not provide you a static IP address and your IP '
+      'address changes evertime you connect to Internet.'),
+
+    _('Your ISP limits incoming connections.'),
+
+    format_lazy(
+        _('PageKite works around NAT, firewalls and IP-address limitations '
+          'by using a combination of tunnels and reverse proxies. You can '
+          'use any pagekite service provider, for example '
+          '<a href="https://pagekite.net">pagekite.net</a>.  In future it '
+          'might be possible to use your buddy\'s {box_name} for this.'),
+        box_name=_(cfg.box_name))
+]
+
 
 def init():
     """Intialize the PageKite module"""

plinth/modules/pagekite/templates/pagekite_introduction.html

@@ -23,51 +23,9 @@
 {% block content %}
   <h2>{{ title }}</h2>
 
-  <p>
-    {% blocktrans trimmed %}
-      PageKite is a system for exposing {box_name} services when
-      you don\'t have a direct connection to the Internet. You only
-      need this if your {{ box_name }} services are unreachable from
-      the rest of the Internet. This includes the following
-      situations:
-    {% endblocktrans %}
-  </p>
-  <ul>
-    <li>
-      {{ box_name }} {% trans "is behind a restricted firewall." %}
-    </li>
-    <li>
-      {{ box_name }}
-      {% blocktrans trimmed %}
-        is connected to a (wireless) router which you don't control.
-      {% endblocktrans %}
-    </li>
-    <li>
-      {% blocktrans trimmed %}
-        Your ISP does not provide you an external IP address and
-        instead provides Internet connection through NAT.
-      {% endblocktrans %}
-    </li>
-    <li>
-      {% blocktrans trimmed %}
-        Your ISP does not provide you a static IP address and your IP
-        address changes evertime you connect to Internet.
-      {% endblocktrans %}
-    </li>
-    <li>
-      Your ISP limits incoming connections.
-    </li>
-  </ul>
-
-  <p>
-    {% blocktrans trimmed %}
-      PageKite works around NAT, firewalls and IP-address limitations
-      by using a combination of tunnels and reverse proxies. You can
-      use any pagekite service provider, for example
-      <a href="https://pagekite.net">pagekite.net</a>.  In future it
-      might be possible to use your buddy's {{ box_name }} for this.
-    {% endblocktrans %}
-  </p>
+  {% for paragraph in description %}
+    <p>{{ paragraph|safe }}</p>
+  {% endfor %}
 
   <p>
     <a class="btn btn-primary btn-md" href="{% url 'pagekite:configure' %}">

plinth/modules/pagekite/views.py

@@ -42,6 +42,7 @@ def index(request):
     """Serve introduction page"""
     return TemplateResponse(request, 'pagekite_introduction.html',
                             {'title': pagekite.title,
+                             'description': pagekite.description,
                              'subsubmenu': subsubmenu})