* On the /uploads/new page, instead of just showing a "This post has
probably already been uploaded" message, show the actual thumbnails of
posts having the same source as what the user is trying to upload.
* Move the iqdb results section up top, beside the related posts section.
This means that the preview will work even when the user doesn't use the
direct image link. e.g. The user can use the bookmarklet on Pixiv
mode=medium pages.
