Move LDBM to the attic

servers/slapd/back-ldbm/Makefile.in

servers/slapd/back-ldbm/add.c

servers/slapd/back-ldbm/alias.c

servers/slapd/back-ldbm/attr.c

servers/slapd/back-ldbm/back-ldbm.h

servers/slapd/back-ldbm/bind.c

servers/slapd/back-ldbm/cache.c

servers/slapd/back-ldbm/close.c

servers/slapd/back-ldbm/compare.c

servers/slapd/back-ldbm/config.c

servers/slapd/back-ldbm/dbcache.c

servers/slapd/back-ldbm/delete.c

servers/slapd/back-ldbm/dn2id.c

servers/slapd/back-ldbm/entry.c

servers/slapd/back-ldbm/extended.c

servers/slapd/back-ldbm/filterindex.c

servers/slapd/back-ldbm/id2children.c

servers/slapd/back-ldbm/id2entry.c

servers/slapd/back-ldbm/idl.c

servers/slapd/back-ldbm/index.c