When a downloaded file's content-type is "application/octet-stream", check the URL to try to determine file type. If the URL includes a query string, it should appear immediately after the part of the URL that has the file extension. If there is no query string, the file extension will be the last part of the URL.
Fixes #93.
When a downloaded file's content-type is "application/octet-stream", check the URL to try to determine file type. If the URL includes a query string, it should appear immediately after the part of the URL that has the file extension. If there is no query string, the file extension will be the last part of the URL.