ldap_defaults.h incorporates non-generated ldapconfig.h values.
ldap_config.h.in is new template for autoconf generated defaults
(namely directories and paths)
ldap_config.h.nt, NT template (must be manually copied)
s/<ldapconfig.h>/<ldap_defaults.h>/
s/DIRSEP/LDAP_DIRSEP/ & s/DEFAULT_/LDAP_/