const'fication

servers/slapd/aclparse.c

servers/slapd/attr.c

servers/slapd/back-ldbm/attr.c

servers/slapd/back-ldbm/cache.c

servers/slapd/back-ldbm/config.c

servers/slapd/back-ldbm/dn2id.c

servers/slapd/back-ldbm/external.h

servers/slapd/back-ldbm/group.c

servers/slapd/back-ldbm/idl.c

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

servers/slapd/backend.c

servers/slapd/bind.c

servers/slapd/charray.c

servers/slapd/config.c

servers/slapd/dn.c

servers/slapd/lock.c

servers/slapd/proto-slap.h

servers/slapd/result.c

servers/slapd/schema.c

servers/slapd/schemaparse.c