Reinstate BINDDN in contrib programs (ITS#391)

[jimd@dutton3.it.siu.edu]

I would like to request that the contrib programs have BINDDN
reinstated as they were under UMich LDAP-3.3. It is important to be able
to distinguish what client is accessing the LDAP server.

Without a BINDDN, ALL contrib client accesses are null connections in
the SLAPD log file. With BINDDN, I can use any reasonable identifier
which is easily understood when examining the SLAPD log file. This
becomes even more important when the LDAP clients are not on the same
host as is the LDAP daemon. Thank you.