Don't allow edit of vendor and effective date in catalog batches.

This may need to be tweaked in the future, but until then we'll be
conservative about it.

tailbone/views/vendors/catalogs.py

@@ -127,6 +127,8 @@ class VendorCatalogCrud(FileBatchCrud):
             del fs.effective
         else:
             del fs.parser_key
+            fs.vendor.set(readonly=True)
+            fs.effective.set(readonly=True)
 
     def init_batch(self, batch):
         parser = require_catalog_parser(batch.parser_key)