Make the indexing configurable

If the index subclass defines a get_queryset method we call it

Author: arnaudlimbourg

src/models.py

@@ -212,7 +212,13 @@ def reindex_all(self, batch_size=1000):
         result = None
         counts = 0
         batch = []
-        for instance in self.model.objects.all():
+
+        if getattr(self, 'get_queryset', None):
+            qs = self.get_queryset()
+        else:
+            qs = self.model.objects.all()
+
+        for instance in qs:
             if self.should_index:
                 attr = getattr(instance, self.should_index)
                 if not attr():