Fix multiple vulnerabilities of ntp.

Approved by: so

Fix multiple ntp vulnerabilities.

Security: FreeBSD-SA-16:24.ntp
Approved by: so

Fix ntp multiple vulnerabilities.

Approved by: so

Fix multiple vulnerabilities of ntp. [SA-16:09]

Fix Linux compatibility layer issetugid(2) system call
vulnerability. [SA-16:10]

Security: FreeBSD-SA-16:09.ntp
Security: FreeBSD-SA-16:10.linux
Approved by: so

o Fix invalid TCP checksums with pf(4). [EN-16:02.pf]
o Fix YP/NIS client library critical bug. [EN-16:03.yplib]
o Fix SCTP ICMPv6 error message vulnerability. [SA-16:01.sctp]
o Fix ntp panic threshold bypass vulnerability. [SA-16:02.ntp]
o Fix Linux compatibility layer incorrect futex handling. [SA-16:03.linux]
o Fix Linux compatibility layer setgroups(2) system call. [SA-16:04.linux]
o Fix TCP MD5 signature denial of service. [SA-16:05.tcp]
o Fix insecure default bsnmpd.conf permissions. [SA-16:06.bsnmpd]

Errata: FreeBSD-EN-16:02.pf
Errata: FreeBSD-EN-16:03.yplib
Security: FreeBSD-SA-16:01.sctp, CVE-2016-1879
Security: FreeBSD-SA-16:02.ntp, CVE-2015-5300
Security: FreeBSD-SA-16:03.linux, CVE-2016-1880
Security: FreeBSD-SA-16:04.linux, CVE-2016-1881
Security: FreeBSD-SA-16:05.tcp, CVE-2016-1882
Security: FreeBSD-SA-16:06.bsnmpd, CVE-2015-5677
Approved by: so

Upgrade NTP to 4.2.8p4.

Security: FreeBSD-SA-15:25.ntp
Security: CVE-2015-7871
Security: CVE-2015-7855
Security: CVE-2015-7854
Security: CVE-2015-7853
Security: CVE-2015-7852
Security: CVE-2015-7851
Security: CVE-2015-7850
Security: CVE-2015-7849
Security: CVE-2015-7848
Security: CVE-2015-7701
Security: CVE-2015-7703
Security: CVE-2015-7704, CVE-2015-7705
Security: CVE-2015-7691, CVE-2015-7692, CVE-2015-7702
Approved by: so

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

english(4) police.

There are 4 key formats, not 3.

PR: 33586
Submitted by: Norihiro Kumagai <kuma@12-225-156-18.client.attbi.com>

mdoc(7) police: This still can be done with one-line display.

Update the mdoc NTP documentation transcribed from the HTML documentation
for ntp-4.1.0.

Unfortunately, David Mills insists on managing the documentation in
such a way as to make it impossible for me to make things easy on our
translators, without printing out the documentation and reading through
it side-by-side with a finger on each page.

mdoc(7) police: sort SEE ALSO xrefs (sort -b -f +2 -3 +1 -2).

Abandon hope of keeping in line with the author's structure,
in favour of placing information in the correct sections.

The ntp_acc(8), ntp_auth(8), ntp_clock(8), ntp_conf(8),
ntp_misc(8) and ntp_mon(8) pages have been merged into
ntp.conf(5) and ntp.keys(5).

Requested by: rgrimes, wollman