Privacy stuff (not full but just to enable /contact for now)

So, this should be mostly working, but we still need to set the visibility for replies to match the visibility of parent comments for now
It basically is, but that's correct.  commentFormWidget' for closures was weird, because the markdown has a different meaning.  It was also getting in the way, because we needed to add a field to comments that didn't make sense for closures (of either type).