Import bmake-20171028

Import bmake-20171028

From ChangeLog

2017-10-28  Simon J. Gerraty  <sjg@bad.crufty.net>

        * VERSION: 20171028
          Merge with NetBSD make, pick up
          o main.c: ignore empty MAKEOBJDIR

        * Makefile.config.in:
          make @prefix@ @machine*@ and @default_sys_path@ defaults.

2017-10-05  Simon J. Gerraty  <sjg@bad.crufty.net>

        * VERSION: 20171005

        * unit-tests/dotwait.mk: redirect stderr through pipe for more
          consistent result on some platforms.

2017-08-13  Simon J. Gerraty  <sjg@bad.crufty.net>

        * machine.sh: entry for AIX

2017-08-12  Simon J. Gerraty  <sjg@bad.crufty.net>

        * VERSION (_MAKE_VERSION): Move the setting of _MAKE_VERSION
          to a file that can be included by configure as well as make.
          This allows configure to set set _MAKE_VERSION in make-bootstrap.sh

2017-08-10  Simon J. Gerraty  <sjg@bad.crufty.net>

        * Makefile (_MAKE_VERSION): 20170810
          Merge with NetBSD make, pick up
          o meta.c: if target is in subdir we only need subdir name in
            meta_name.