Control empty submission behavior

You can now control the Dromo importer's behavior on the review screen when 0 rows will be imported. This can occur when the import data is empty, or if invalidDataBehavior is set to REMOVE_INVALID_ROWS (the default) and all rows have at least one error. 

By default, Dromo will continue to allow empty submissions. However, you can change this behavior with the new allowEmptySubmit setting. When set to false, the Dromo importer will not allow the user to submit an import if no result rows would be submitted.