MFC r310609: Don't use high precision clock for expiration as only second
portion is used.

MFC r310608: Avoid use after free.

MFC: r262136

Remove the 3rd clause ("advertising clause") of the BSD license as
permitted by the University of Berkeley on July 22, 1999.

Reviewed by: imp

MFC: r262136

Remove the 3rd clause ("advertising clause") of the BSD license as
permitted by the University of Berkeley on July 22, 1999.

Reviewed by: imp