Adjust XMLTV output to try to make it validate using tv_validate_file.

The tag ordering and some attributes had to be adjusted.  Note, this change
is not tested, as I lack a test setup for running the code.

This should fix issue Frikanalen#103.

fkbeta/templates/agenda/xmltv.xml

@@ -1,23 +1,22 @@
 <tv generator-info-name="fkbeta.agenda.xmltv">
   <channel id="{{ channel_id }}">
-    <url>{{ site_url }}</url>
     {% for channel_display_name in channel_display_names %}
       <display-name>{{ channel_display_name }}</display-name>
     {% endfor %}
+    <url>{{ site_url }}</url>
   </channel>
   {% for program in events %}
     <programme
-      id="{{ channel_id }}"
-      start="{{ program.starttime|date:'YmdHis O' }}"
-      end="{{ program.endtime|date:'YmdHis O' }}">
+      channel="{{ channel_id }}"
+      start="{{ program.starttime|date:'YmdHis O' }}">
     {% if program.video %}
       <title lang="no">{{ program.video.name }}</title>
-      <desc lang="no"></desc>
+      <desc lang="no">{{ program.video.header }}</desc>
       <url>{{ site_url }}{{ program.video.get_absolute_url }}</url>
-      <length unit="seconds">{{ program.video.duration.seconds }}</length>
+      <length units="seconds">{{ program.video.duration.seconds }}</length>
     {% else %}
       <title lang="no">{{ program.default_name }}</title>
-      <length unit="seconds">{{ program.duration.seconds }}</length>
+      <length units="seconds">{{ program.duration.seconds }}</length>
     {% endif %}
     </programme>
   {% endfor %}