[FIX] have one list of notifications

[IMP] use a nice formatting to show notifications for imported file

account_bank_statement_import/models/account_bank_statement_import.py

@@ -94,7 +94,7 @@ class AccountBankStatementImport(models.TransientModel):
                 self._import_statement(stmt_vals))
             if statement_id:
                 statement_ids.append(statement_id)
-            notifications.append(new_notifications)
+            notifications.extend(new_notifications)
         if len(statement_ids) == 0:
             raise Warning(_('You have already imported that file.'))
         return statement_ids, notifications

account_bank_statement_import_save_file/models/account_bank_statement_import.py

@@ -46,5 +46,7 @@ class AccountBankStatementImport(models.TransientModel):
             'res_id': statement_id,
             'type': 'binary',
             'datas': base64.b64encode(data_file),
-            'description': notifications,
+            'description': '\n'.join(
+                '%(type)s: %(message)' % notification
+                for notification in notifications) or False,
         }