Refactor purchasing batch views to use master3

tailbone/views/purchasing/ordering.py

@@ -86,6 +86,12 @@ class OrderingBatchView(PurchasingBatchView):
     def batch_mode(self):
         return self.enum.PURCHASE_BATCH_MODE_ORDERING
 
+    def configure_form(self, f):
+        super(OrderingBatchView, self).configure_form(f)
+
+        # purchase
+        f.remove_field('purchase')
+
     def order_form(self):
         """
         View for editing batch row data as an order form.