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

mdoc: remove superfluous paragraph macro.

- Document that sem_wait() can fail with EINTR if it is interrupted by a
signal.
- Fix the old ksem implementation for POSIX semaphores to not restart
sem_wait() or sem_timedwait() if interrupted by a signal.

MFC after: 1 week

Add missing section number.

In file sem_timewait.3, remove reference to SYSV semphore in SEE ALSO
section, sync it with sem_wait.3.

Cross-reference sem_getvalue(3) from several other semaphore-related
functions.

MFC after: 3 days

Markup tidying.

- libc/sys/sem.c was repocopied to libc/gen/sem.c.
- sem_*(3) manpages were repocopied from libc_r.

Reviewed by: deischen
Repocopy by: markm

The .Fn function. Use .Xr where appropriate.

Cross reference sem(4) so users know which kernel options are required
to use these semaphore functions.

mdoc(7) police: Use the new .In macro for #include statements.

Use ``.Rv -std'' wherever possible.

Submitted by: yar

Spell "FreeBSD" with "F" and "BSD" in uppercase.

Remove whitespace at EOL.

Use ``.St -p1003.1-96''.

Change my email address in the copyright notices for the sake of consistency
(jasone@canonware.com --> jasone@freebsd.org).

Introduce .Lb macro to libc_r manpages.

Add man pages for the sem_*() functions.

Approved by: jkh