fixed closed_content loop and following permissions

I added an inclusion option `closed_view` so that you can do something like
{{ _self | tip; closed_view: blank }} 
hmm, I'm not sure we're ready for this.  In general we want to be really slow to add nest syntax, because then we have to support it forever (or migrate and communicate, which is a pain).

I do think we may want something like this some day, but we usually have a lot of discussion before messing with nest syntax. I've wondered whether we want to be able to set a denial view or a missing view or something. The closed_view hasn't come up before, actually, because this typically varies with view not with nest (and should probably be part of the view API).