Revert "render messages as markdown"

This reverts commit 65de4ed8d1.

Looks pretty bad.

conversations/templates/conversations/_message_detail.html

@@ -1,10 +1,8 @@
-{% load proposals_tags %}
-
 <div class="panel panel-{% block panelstyleblock %}default{% endblock %}">
   <div class="panel-heading">
     {{ message.created }} | <a href="{% url 'show-speaker' message.author.username %}">{{ message.author.profile }}</a>
   </div>
   <div class="panel-body">
-    {% markdown message.content %}
+    {{ message.content|linebreaksbr }}
   </div>
 </div>

conversations/templates/conversations/emails/message.html

@@ -1,4 +1,4 @@
-{% load proposals_tags %}{% markdown content %}
+{{ content|linebreaksbr }}
 
 <hr>
 {% if answering %}

conversations/templates/conversations/emails/talk_notification.html

@@ -1,11 +1,11 @@
-{% load proposals_tags %}Hi!<br />
+Hi!<br />
 <br />
 A <a href="https://{{ uri }}">new {{ talk.event }}</a> has been proposed by <a href="https://{{ proposer_uri }}">{{ proposer.profile }}</a>!<br />
 <br />
 Title: {{ talk.title }}<br />
 <br />
 Description:<br />
-<p>{% markdown talk.description %}</p>
+<p>{{ talk.description|linebreaksbr }}</p>
 {% if answering %}
 <hr>
 Reply to this email directly to comment this talk.{% endif %}