Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

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

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

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

libutil: Use O_CLOEXEC for internal file descriptors from open().

Remove California Regent's clause 3, per letter

ANSIfy, WARNSify, CONSTify. Bit of style(9)-ify.

Tidy up. Sort headers.

Add __FBSDID()s to libutil

Correct uu_lock_txfr. I don't think this ever worked correctly.

$Id$ -> $FreeBSD$

Get the pid right if a stale lock file exists.
PR: 10531
Submitted by: Lawrence D. Lopez <lopez@cisco.com>

Cast pid_t to int for sprintf.
Pointed out by: Charlie Sorsby <crs@hgo.net>

Add uu_lock_txfr() to transfer ownership of a successful
uu_lock() to another process.

Implement canonical locking protocol
Suggested by: joerg

Improve weak locking by using flock()

Make uu_* const correct.

Suggested by: joerg

Add Id
Reduce space for error bufer from 512 to 128: there is no such long strings
can be returned from strerror()

Code space optimization in uu_lockerr()

Remove unused USE_PERROR define and syslog.h include
Use snprintf instead of sprintf to avoid buffer overflows
Use snprintf in uu_lockerr instead of lots of hardcoded constants
and not null-terminated strncpy
Return "" for OK and "device in use" for INUSE, it allows simple
strcpy(buf, uu_lockerr(retcode)) without testing for special OK
case (NULL was there) and obtaining meaningful result for INUSE
("" was there) without special testing for it too.

Remove the syslog stuff, and allow various return values
in uu_lock(). Add uu_lockerr() for turning the results of
uu_lock into something printable. Remove bogus section in man page
about race conditions allowing both processes to get the lock.
Include libutil.h and use uu_lock() correctly where it should.

Suggested by: ache@freebsd.org

Move uucplock into libutil and create a manual page.