Remove comments about default daemon_flags; most are empty, those

Remove comments about default daemon_flags; most are empty, those
that aren't are redundant because they can be found in the rc.d(8)
scripts themselves, and they risk getting out of sync.
While here, sort the daemons alphabetically.
No functional change.

Triggered by a much smaller nameserver-only patch from stephan@.
OK ajacoutot@ rpe@ stephan@ and looks good to sthen@.