Update build tools based upon OPENLDAP_AC work

acconfig.h

acinclude.m4

aclocal.m4

build/ltmain.sh

build/missing

build/openldap.m4

configure

configure.in

include/Makefile.in

include/lber_types.hin

include/ldap_config.hin

include/ldap_features.hin

include/portable.hin

libraries/libldap/os-local.c

libraries/liblutil/getpeereid.c

libraries/liblutil/passwd.c

libraries/librewrite/xmap.c

servers/slapd/back-ldbm/dbcache.c

servers/slapd/back-ldbm/ldbm.c

servers/slapd/back-passwd/search.c