* Makefile.in (exec_prefix): New variable.

* Makefile.in (exec_prefix): New variable.
	(bindir, libdir): Use it instead of `prefix'.

	* Makefile.in (CFLAGS): #define HAVE_CONFIG_H, too.

	* Makefile.in (libdir): Default to ${prefix}/lib.
	(archlibdir): Adjusted to match.

	* Makefile.in (distclean): Don't delete backup or autosave files.
	(extraclean): Like realclean, but does delete backup and autosave
	files.

	* Makefile.in (realclean): Ignore errors from rm.

	* Makefile.in (distclean): Don't bother to delete ../arch-lib;
	that doesn't exist anymore.

	* Makefile.in (prefix, bindir, libdir, srcdir): New variables, as
	described in the top-level Makefile.
	(UTILITIES): Add make-path to the list of utility programs.
	(../arch-lib): Replaced by the ${archlibdir} target, which places
	the executables in their permanent home.
	(install, install.sysv, install.xenix): Consolidated into one
	target which should work under all circumstances, modulo a few
	ignored error messages.