MFC r357756: backup-passwd: mask out all passwords in the diff

The previous expression borked if a username had a plus or hyphen in it.
This is needlessly restrictive- at leSt a hyphen in the middle is valid.
Instead of playing this game, let's just assume the username can't contain a
colon and mask out the second field.

MFC r326074: filter all passwords (not only changed) from periodic passwd backup

The periodic 200.backup-passwd script outputs any differences it finds
in master.passwd, relative to the previous backup. It intends to elide
the encrypted password field, but previously did so only for changed
lines (i.e., those beginning with - or + in the diff).

Apply the sed expression also to unchanged lines to also elide their
passwords.

PR: 223461
Reported by: Andre Albsmeier
Sponsored by: The FreeBSD Foundation

MFC: r322726

Bring back the much more readable unified format for differences in
/etc/{group,master.passwd}. This was originally turned on for all of
/etc/{aliases,group,master.passwd} in r55196, but then backed out
only for the latter two in r56697, as the adaption of the sed(1)ing
done in r56308 was incorrect. This left us with inconsistent diff(1)
formats in the daily output of periodic(8) ever since, despite in
r56697 having been promised to be revisited. So properly adapt the
password hash filtering to the unified format and turn the later on
again for /etc/{group,master.passwd}, too.

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

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

After further discussion on -CURRENT, some people (jhb) do not like
the idea of not masking passwords on comments in case the
administrator comments out an entry without clearing the
password. Instead completely ignore comments (since they have no
security impact) when doing the diff of the old and new passwd file.

Suggested by: rwatson

No need to hide stuff in the $FreeBSD$ tag or in other comments like,

Backup passwd and group files:
1c1
< # $FreeBSD:(password):09:07 peter Exp $
---
> # $FreeBSD:(password):27:16 ache Exp $

MFC after: 1 week

Another overhaul of the periodic stuff.

All periodic sub-scripts <larf> now have their return codes interpreted
by periodic(8). Output may be masked based on variable values in
periodic.conf.

It's also now possible to email periodic output to arbitrary addresses,
or to send it to a log file, examples of which can be found in
newsyslog.conf.

The upshot of it all should be no discernable changes to the default
behaviour of periodic(8).

PR: 21250

Introduce /etc/defaults/periodic.conf, similar in concept to rc.conf.
The only change in the default functionality should be that
the output reports are slightly more verbose WRT files deleted.

Not objected to by: freebsd-arch

Revert to rev 1.3 since the sed'ing is wrong. Revisit this after 4.0-RELEASE.

Update the sed action to match the change to "diff -u".
Otherwise the encrypted password of any account who's information changed
was shown in the daily email to root.

Submitted by: jhb

Use the *much* more readable unified diff format.

$Id$ -> $FreeBSD$

Add a chkgrp run after backing up the passwd and group files.

Suggested-by: Andreas Klemm

This commit was generated by cvs2svn to compensate for changes in r28263,
which included commits to RCS files with non-trunk default branches.

Copy /etc/cron.d to /etc/periodic per-request of many.
This wasn't done with a repository copy because there was no
history of any consequence. Flames to me.