Bug fix---socketpairs don't have an address family.

Hmm ... socketpairs don't have an address family like we know it.  There will
be plenty of fixes to this codebase to handle that.
Add some comments to list some option standards.
Bug fix---some Unix systems actually have comments (!) in /etc/passwd

It seems that Apple decided to add comments to the /etc/passwd and etc/group
/files.  Hmm ...  didn't see that one coming.