Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.Approved by: re (implicit)Sponsored by: The FreeBSD Foundation
Build usr.bin/ with WARNS=6 by default.Also add some missing $FreeBSD$ to keep svn happy.
Add revoke(1).While hacking on TTY code, I often miss a small utility to revoke my own(pseudo-)terminals. This small utility is just a small wrapper aroundthe revoke(2) call, so you can destroy your very own login sessions.Approved by: re