cupsd prevents disc spin-down

[bumpelo at comcast.net]

cupsd seems to periodically re-write the file /etc/cups/certs/0 even when nothing is going on. This prevents the hard disc from going in to sleep mode. Even if it were to have a shorter sleep cycle, this behavior would just wake it up every few minutes.

noflushd is not able to postpone the flushing of this, which probably means it is a syncronous write.

This is bad behavior for an idle daemon.