don't list tracks that were not on air in recent diffusions

nonstop/models.py

@@ -15,7 +15,8 @@ class Artist(models.Model):
         return reverse('artist-view', kwargs={'pk': self.id})
 
     def recent_diffusions(self):
-        return SomaLogLine.objects.filter(filepath__track__artist=self).order_by('-play_timestamp')
+        return SomaLogLine.objects.filter(filepath__track__artist=self
+                ).exclude(on_air=False).order_by('-play_timestamp')
 
 
 class Album(models.Model):
@@ -42,7 +43,8 @@ class Track(models.Model):
         return reverse('track-view', kwargs={'pk': self.id})
 
     def recent_diffusions(self):
-        return SomaLogLine.objects.filter(filepath__track=self).order_by('-play_timestamp')
+        return SomaLogLine.objects.filter(filepath__track=self
+                ).exclude(on_air=False).order_by('-play_timestamp')
 
 
 class NonstopFile(models.Model):