User Permissions per Notebook rather than per Project

[03rcooke]

It would be awesome if we could set permissions for users per notebook within projects. For instance I might want to allow Joe Bloggs access to a single notebook within a larger project. I could see that this could be a matrix as part of the Project > Settings page where you could tick which notebooks each user had access to, or it could be added as functionality when you edit a notebook through the more options menu.

Don't know if this function is actually feasible/possible/practical though so feel free to close issue if it can't be done.

#enhancement