Upload tool does not fail properly.

When uploading datasets that should fail (e.g. html datatsets), the info field has an error message, but the dataset is green and empty (it should be red).

When uploading files via URL, http status codes are not relayed when they are errors. e.g. a 404 URL will create an empty green dataset that often says `The uploaded file contains inappropriate HTML content`` (The 404 error page is html...). This should be a red dataset and report the error code and message.