- Copy stable/10 (r259064) to releng/10.0 as part of the
10.0-RELEASE cycle.
- Update __FreeBSD_version [1]
- Set branch name to -RC1

[1] 10.0-CURRENT __FreeBSD_version value ended at '55', so
start releng/10.0 at '100' so the branch is started with
a value ending in zero.

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

Fix header guards.

This was ready about the same time as r251862 so just make one final cleanup

Submitted by: dt71@gmx.com

Clean up -Wheader-guard warnings.

Submitted by: <dt71@gmx.com>
MFC after: 3 days
X-MFC with: r251848

- Update Oleg Moskalenko's email address

Requested by: Oleg Moskalenko <mom040267@gmail.com>

- Remove forgotten commented out debug code

Submitted by: Christoph Mallon <christoph.mallon@gmx.de>
Reviewed by: Oleg Moskalenko <oleg.moskalenko@citrix.com>

- Simplify and unify diagnostic and error message handling

Submitted by: Christoph Mallon <christoph.mallon@gmx.de>
Reviewed by: Oleg Moskalenko <oleg.moskalenko@citrix.com>

- Change the memory heuristics to an actually working one

Submitted by: Oleg Moskalenko <oleg.moskalenko@citrix.com>
Prodded by: kib

- Use unsigned int for values obtained with sysctlbyname(). This fixes
sparc64 performance problems.

Submitted by: Oleg Moskalenko <oleg.moskalenko@citrix.com>
Tested by: trasz

- Portability changes for ARM
- Allow larger sort memory on 64-bit platforms

Submitted by: Oleg Moskalenko <oleg.moskalenko@citrix.com>

More -Wmissing-variable-declarations fixes.

In addition to adding `static' where possible:

- bin/date: Move `retval' into extern.h to make it visible to date.c.
- bin/ed: Move globally used variables into ed.h.
- sbin/camcontrol: Move `verbose' into camcontrol.h and fix shadow warnings.
- usr.bin/calendar: Remove unneeded variables.
- usr.bin/chat: Make `line' local instead of global.
- usr.bin/elfdump: Comment out unneeded function.
- usr.bin/rlogin: Use _Noreturn instead of __dead2.
- usr.bin/tset: Pull `Ospeed' into extern.h.
- usr.sbin/mfiutil: Put global variables in mfiutil.h.
- usr.sbin/pkg: Remove unused `os_corres'.
- usr.sbin/quotaon, usr.sbin/repquota: Remove unused `qfname'.

Remove WARNS=6 lines.

WARNS=6 is already implied at this point.

- Remove GNU sort and the WITH_GNU_SORT knob

Remove trailing whitespace.

- Change --nthreads parameter to --parallel for GNU compatibility
- Change default sort method to mergesort, which has a better worst case
performance than qsort

Submitted by: Oleg Moskalenko <oleg.moskalenko@citrix.com>

- Switch to BSD sort as default sort. GNU sort will still be installed as
"gnusort". Most of the BSD sort development work was done by
Oleg Moskalenko <oleg.moskalenko@citrix.com>.
- GNU grep can be set to default by setting WITH_GNU_GREP. It will cause
BSD sort to be installed as "bsdsort".

Portbuild tested by: linimon

- Disable threaded sort by default
- Fix typo in the NLS support

- Remove the UNUSED_ARG macro and use __unused in argument lists

Reviewed by: dim
MFC after: 3 days

In usr.bin/sort, use another method of silencing warnings about unused
arguments, which does not trigger self-assignment warnings in certain
circumstances (for example, using clang with ccache).

MFC after: 3 days

mdoc: sort sections into conventional order.

- Only use multi-threading for large files
- Do not use mmap() by default; it can be enabled by --mmap
- Add some minor optimizations for -u
- Update manual page according to the changes

Submitted by: Oleg Moskalenko <oleg.moskalenko@citrix.com>

- Fix -o option that was broken by my clang compile fix

Submitted by: Oleg Moskalenko <oleg.moskalenko@citrix.com>

- Eliminate initializations if global variables. Compilers are not
required to optimize these so it may result in larger binary size.

Pointed out by: kib

- Update catalogs

- Fix build with clang

Add a BSD-licensed sort rewrite that was started by me and later completed
with the major functionality and optimizations by Oleg Moskalenko.
It is compatible with the latest version of POSIX and the current GNU sort
version that we have in base. Beside this, it implements all the
functionality introduced in later versions of GNU sort. For now, it will
be installed as "bsdsort", keeping GNU sort as the default sort
implementation.