Fix some things for inventory batch views

tailbone/views/batch/core.py

@@ -445,7 +445,9 @@ class BatchMasterView(MasterView):
 
     def toggle_complete(self):
         batch = self.get_instance()
-        if not batch.executed:
+        if batch.executed:
+            self.request.session.flash("Request ignored, since batch has already been executed")
+        else:
             form = forms.Form(schema=ToggleComplete(), request=self.request)
             if form.validate(newstyle=True):
                 batch.complete = form.validated['complete']

tailbone/views/inventory.py

@@ -194,9 +194,6 @@ class InventoryBatchView(BatchMasterView):
             batch.created_by,
             localtime(self.request.rattail_config, batch.created, from_utc=True).strftime('%Y-%m-%d'))
 
-    def editable_instance(self, batch):
-        return True
-
     def mutable_batch(self, batch):
         return not batch.executed and not batch.complete and batch.mode != self.enum.INVENTORY_MODE_ZERO_ALL