Remove unsupported build facilities.

Remove unsupported build facilities.

Over time the non-standard build and install systems (nmake files,
smake files, Visual Studio project files, etc.) have atrophied and
maintaining them is not worth the effort, for such a simple utility
as make.  Remove all the non-standard build tool support and unify
OS-specific build rules under a basic set of (GNU make) makefiles.

Preserve the existing bootstrapping scripts (for POSIX, Windows,
and MS-DOS).  Also the existing VMS build scripts are left unchanged:
I don't have enough experience with VMS to venture into this area.
Perhaps one of the VMS maintainers might like to determine whether
conversion would be appropriate.

Rather than create libraries for w32 and glob (non-POSIX), simply
link the object files directly to remove the complexity.

* NEWS: Update with user-facing notes.
* Makefile.am: Clean up to use the latest automake best practices.
Build Windows code directly from the root makefile to avoid recursion.
* README.Amiga, README.DOS.template, README.W32.template: Updated.
* INSTALL: Point readers at the README.git file.
* maintMakefile: Remove obsolete files.  Create Basic.mk file.
* Basic.mk.template, mk/*.mk: Create basic GNU make-based makefiles.
* build_w32.bat: Copy Basic.mk to Makefile
* configure.ac: We no longer need AM_PROG_AR.
* dosbuild.bat: Rename to builddos.bat.  Incorporate configure.bat.
* Makefile.DOS.template: Remove.
* NMakefile.template, w32/subproc/NMakefile: Remove.
* SMakefile.template, glob/SMakefile, glob/SCOPTIONS, make.lnk: Remove.
* configure.bat, glob/configure.bat: Remove.
* w32/Makefile.am: Remove.
* make_msvc_net2003.sln, make_msvc_net2003.vcproj: Remove.