Add support for bulk-delete of Pricing Batches

tailbone/views/master.py

@@ -675,12 +675,19 @@ class MasterView(View):
         if self.request.method == 'POST':
             query = self.get_effective_query(sortable=False)
             count = query.count()
-            query.delete(synchronize_session=False)
+            self.bulk_delete_objects(query)
             self.request.session.flash("Deleted {:,d} {}".format(count, self.get_model_title_plural()))
         else:
             self.request.session.flash("Sorry, you must POST to do a bulk delete operation")
         return self.redirect(self.get_index_url())
 
+    def bulk_delete_objects(self, query):
+        # TODO: sometimes the first makes sense, and would be preferred for
+        # efficiency's sake.  might even need to add progress to latter?
+        # query.delete(synchronize_session=False)
+        for obj in query:
+            self.Session.delete(obj)
+
     def get_merge_fields(self):
         if hasattr(self, 'merge_fields'):
             return self.merge_fields