Allow to reorder fields.

base_export_manager/views/ir_exports_view.xml

@@ -43,7 +43,7 @@
                 <field name="export_fields" nolabel="1"
                        context="{'default_model1_id': model_id}">
                     <tree editable="bottom">
-                        <field name="sequence" invisible="True"/>
+                        <field name="sequence" widget="handle"/>
                         <field name="model1_id" invisible="True"/>
                         <field name="model2_id" invisible="True"/>
                         <field name="model3_id" invisible="True"/>