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

Add support for netgroup, based on patch in the PR but made consistent
with existing style.

PR: bin/132692

Teach getent(1) to look up a hostname and find IPv6 addresses.

PR: bin/161548
Submitted by: matthew

Print INIT_PROCESS and LOGIN_PROCESS entries as well.

Even though our implementation of utmpx never emits these types of
records, they are part of POSIX. Do print them when they show up in the
database files.

While there, also print the type number of unsupported records.

Change how getent utmpx works.

- Always require active, log or lastlogin to be provided.
- Allow the user to provide custom filenames.

The NetBSD Foundation has granted permission to remove clause 3 and 4
from their software.

Obtained from: NetBSD

Also print UNIX timestamps in getent utmpx output.

Also let getent(1) print values of ut_pid.

Allow getent(1) to display utmpx entries as well.

Because getutxent also matches the typical get*ent format of library
routines, I thought it would be a good idea to teach it how to read
utmpx databases. getent(1) just gives a raw dump, which is very useful
when debugging problems related to parsing/logging.

cleanup code: remove superfluous comma at end of enumeration
declaration, remove useless "break" after exit(3) call, and add a
missing va_end(3) call.

The port number must be network byte order.

o By popular demand import getent(1) utility: a program retrieves
and displays entries from the administrative database specified by
database, using the lookup order specified in nsswitch.conf(5).

PR: bin/79903, bin/88460, bin/96536
Submitted by: Julien Gabel, Dan Nelson, Daniel J. O'Connor
Obtained from: NetBSD
Discussed with: ume, soc-bushman
MFC after: 1 month