Bug 20462

	The periodic(8) service executes shell scripts at specific
times.  There is currently no way to customize those scripts except
for editing them.  After doing this, one has to remember to merge
local changes after any operating system update.

The following patches propose a change to the scripts.  They will use
a technique similar to rc.conf(5) to read a global configuration file
(/etc/defaults/periodic.conf) and a local override file
(/etc/periodic.conf).  With the included /etc/defaults/periodic.conf
the scripts will run as before, so the merge won't change the system
drasticly.  rc.conf(5) now includes a new option (periodic_conf_files)
to customize the searchpath for local periodic configuration files.

At the moment most of the possible options are boolean and they are
used to enable or disable a particular script.  But one can imagine to
include any sort of option to allow local modifications
(cf. daily_status_network_args, daily_status_mail_rejects_logpath and
weekly_noid_searchpaths in /etc/defaults/periodic.conf).

The appended patch includes three files:
- etc.patch  includes the patches to the scripts and a 
  /etc/defaults/periodic.conf
- periodic.patch includes the new manpage periodic.conf(5), 
  a patch to the periodic(5) man page to reference the new page and
  a patch to the Makefile to install it
- share.patch includes a patch to the rc.conf(5) man page to reference
  the new option.

All patches should be installed in /usr/src with 'patch -p0'.

I didn't want to change too much inside the scripts currently used.  I
think it's easier to supply patches to a single script when this patch
is available in CURRENT and STABLE.

The manpage should probably be reviewed by someone with english as
native language.  And currently the manpage contains a reference to
FreeBSD 5.0.  This should be changed if this patch is MFC'd and
appears in 4.x-STABLE.


Feel free to contact me,
Stefan