Make upload_dataset(progress=) and download_dataset(quiet=) consistent

[mortenpi]

download_dataset has a quiet argument to suppress rclone's stdout (and other stuff). In #48 we added progress to upload_dataset (which decides whether to pass --progress to rlcone). We should make the arguments consistent somehow, but their behavior is subtly different.

1. Just use quiet, deprecate progress.
2. Just use progress, deprecate quiet.
3. Use both, because their behavior is different.

I'm partial to (1): rclone is an implementation detail, so the only thing we can really promise is that there is no output at all, from anywhere.