ldap_get_dn(3) on macOS

The text 25a609c61424, as Mac OS X 10.7.5, Mac OS X 10.7.4, Mac OS X 10.7.3, Mac OS X 10.7.2, Mac OS X 10.7.1, Mac OS X 10.7 shipped it.

LDAP DN handling routines

ldap_get_dn(3) on macOS now