Thumbnail as a config?

[derek-adair]

My use case is to upload a thumbnail / cropped photo to the same backend I am storing it in. It looks like the thumbnail backend only stores things locally, but maybe i've read the code wrong.

[skoczen]

Just read through - that was from a PR probably two years old, so I'd completely forgotten. To my eyes, it looks like it'll use the storage backend for saves/thumbnailing, but that os.unlink isn't backend-linked or compatible. Could definitely use improvement.