SFTP: make it so files can be downloaded into resources or upload from resources

Fixes #428
> We are using Sami for generation the API docs.

Don't they both use the same format for comments? Maybe the way they render the comments is different, maybe one is easier to install, maybe one is more extensible, etc, but I was under the impression that what was syntactically correct in one is syntactically correct in the other?

Regardless, I've changed it..