Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Remove advertising clause from University of California Regent's license,
per letter dated July 22, 1999.

Approved by: core, imp

Backed out removal of vendor id and gratuitous change of tmpfile prefix
in previous commit.

10 X's for mkstemp(), and don't redefine _PATH_TMP

Look for boot blocks in new default location.

BSD 4.4 Lite sbin Sources

Note: XNSrouted and routed NOT imported here, they shall be imported with
usr.sbin.