For automation tools it is way easier to maintain files in directories rather
than modifying /etc/crontab.
The files in those directories are in the same format as /etc/crontab
Reviewed by: adrian
MFC after: 2 weeks
Relnotes: yes
Sponsored by: Gandi.net
Differential Revision: https://reviews.freebsd.org/D8400
Note, that when cron(8) cannot create pidfile, it'll exit. I didn't
changed this behaviour, but its better to ignore errors other than
EEXIST, so daemon can be started on systems where /var/ file system
doesn't support locking (like NFS without rpc.lockd(8)).
for any reason other than ENOENT (think resource limits). Close allow and
deny files before allowed() returns to stop the user's EDITOR being able to
read them.
Obtained from: OpenBSD (partially)
This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.
Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.
