Image uploading now expects a file. Refactor image uploading to not expect a Django UploadedFile and use a regular file instead. This will be needed for the future feature of being able to save and upload images from the Internet.

#downloads-add td {
    padding-bottom: 5px;
}

#downloads-add fieldset {
    margin: 1em 0 1em;
    padding: 0.5em;
}