include a class marking if tracks were on air

nonstop/templates/nonstop/somalogline_archive_day.html

@@ -15,7 +15,7 @@
 
 <ul class="soma-list">
     {% for somalog in object_list %}
-        <li><span class="timestamp">{{ somalog.play_timestamp|date:"H:i" }}</span>:
+        <li class="on-air-{{ somalog.on_air }}"><span class="timestamp">{{ somalog.play_timestamp|date:"H:i" }}</span>:
             {% if somalog.filepath.track %}
             <a href="{{ somalog.filepath.track.get_absolute_url }}" class="tracktitle">{{ somalog.filepath.track.title }}</a>
             <span class="trackartist">(<a href="{{ somalog.filepath.track.artist.get_absolute_url }}" class="trackartist">{{ somalog.filepath.track.artist.name }}</a>)</span>