Preserve access permissions of documents

[ikalnytskyi]

As a user I interested in preserving access permissions for my documents. In other words, when source processor reads documents from filesystem, it needs additionally to read their access permissions (chmod), owner and group. Then, when it comes to commit processor, the latter should use them on output documents.

There are multiple cases when this might be handy. Maybe someone wants to copy some files to output directory, but forbid access to it for web server. Or vice versa, give access only for nginx group, so only its owner and nginx user will have access to it. Alternatively, it could be done by separate (external) script (or commands). But why to ignore something we can implement? :)

P.S: Alternatively, someone may decide to use permissions, owner and/or group in when conditions.