several rc.d scripts are installed by the FreeBSD-rc package, but they
don't work without their respective packages installed. move these rc
scripts into the appropriate packages so they're installed along with
the services they start.
this should be undisruptive to users since the scripts don't work
without those packages installed anyway. (for this reason, do not move
the Kerberos scripts, because the MIT Kerberos port uses the base rc.d
scripts.)