Remove template files to simplify distribution creation

Remove template files to simplify distribution creation

The README templates were not useful since the replacement step
didn't have anything to replace: rename them.

Rather than creating template files for the config variants, create
mkconfig.h.in containg PACKAGE_* variables to be replaced, and have
config variant header files include it.  Note on POSIX we don't use
this, and continue to generate a single config.h.in file.

Use config.status to convert the README.in and mkconfig.h.in files
during distribution creation.

Modify all users of VERSION to use PACKAGE_VERSION instead.

* configure.ac: Use GNU Make not GNU make as the package name.
* README.in: Use GNU Make not GNU make.
* README.git: Remove references to README.W32.template.
* .gitignore: Update for new behavior.
* Basic.mk.template: Remove unused posix_SOURCES and VERSION, and
references to unshipped mk/Posix.mk
* Makefile.am: Add src/mkconfig.h as an extra dist file.
* bootstrap.bat: Rewrite mkconfig.h.in to mkconfig.h
* maintMakefile: Remove obsolete template files; add mkconfig.h.in.
* prepare_vms.com: Rewrite mkconfig.h.in to mkconfig.h
* mk/VMS.mk: Fix incorrect header file prerequisite.
* src/mkconfig.h.in: New file containing PACKAGE variables.
* src/config.ami: Include mkconfig.h.
* src/config.h.W32: Ditto.
* src/configh.dos: Ditto.
* src/config.h-vms: Ditto.
* src/version.c: Use PACKAGE_VERSION not VERSION.