Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

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

Allow the location of the INDEX file to specified to pkg_version.
This is particularly convenient on a cluster of machines to prevent
having to rebuild the INDEX file on each.

Reviewed by: portmgr

Add a pkg_version variable so that it's possible to run portsversion instead
of pkg_version in periodic/weekly/400.status-pkg.

Recognize and support new output which pkg_version(1) might produce.

PR: 27707
Approved by: bmah, markm

Remind the user that they need to check CPAN manually for updates
to perl5 modules installed by hand.

Identify obsolete ports

Cope with ports that have multiple versions *and* have embedded ``-''s
in their name.

Understand ``multiple versions'' lines emitted from pkg_version.

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

Add weekly_status_pkg_enable (defaults to NO)