Port adminutil to use openldap
    
    This allows adminutil to build with either openldap or mozldap.  Use the
    --with-openldap switch to use openldap.  By default, it will use mozldap.
    Most of the API changes are to allow passing the security directory to
    the lower level ldap code - instead of the global NSS context, openldap
    uses its own context, so needs to be passed the security dir via the
    ldap_set_option(ld, LDAP_OPT_X_TLS_CACERTDIR, securitydir) api.