Use Gnulib's version-etc-fsf' for --version' and `--help' output.

* m4/gnulib-cache.m4: Add `version-etc-fsf'.  Switch to LGPLv3+.

* GUILE-VERSION (PACKAGE): Change to "GNU Guile".

* Makefile.am (distdir): New variable.

* libguile/script.c (scm_shell_usage): Improve formatting.  Use
  `emit_bug_reporting_address ()'.
  (scm_compile_shell_switches): Use `version_etc ()'.

m4/stdarg.m4

@@ -0,0 +1,67 @@
+# stdarg.m4 serial 3
+dnl Copyright (C) 2006, 2008-2009 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+dnl From Bruno Haible.
+dnl Provide a working va_copy in combination with <stdarg.h>.
+
+AC_DEFUN([gl_STDARG_H],
+[
+  STDARG_H='';                AC_SUBST([STDARG_H])
+  NEXT_STDARG_H='<stdarg.h>'; AC_SUBST([NEXT_STDARG_H])
+  AC_MSG_CHECKING([for va_copy])
+  AC_CACHE_VAL([gl_cv_func_va_copy], [
+    AC_TRY_COMPILE([#include <stdarg.h>], [
+#ifndef va_copy
+void (*func) (va_list, va_list) = va_copy;
+#endif
+],
+      [gl_cv_func_va_copy=yes], [gl_cv_func_va_copy=no])])
+  AC_MSG_RESULT([$gl_cv_func_va_copy])
+  if test $gl_cv_func_va_copy = no; then
+    dnl Provide a substitute.
+    dnl Usually a simple definition in <config.h> is enough. Not so on AIX 5
+    dnl with some versions of the /usr/vac/bin/cc compiler. It has an <stdarg.h>
+    dnl which does '#undef va_copy', leading to a missing va_copy symbol. For
+    dnl this platform, we use an <stdarg.h> substitute. But we cannot use this
+    dnl approach on other platforms, because <stdarg.h> often defines only
+    dnl preprocessor macros and gl_ABSOLUTE_HEADER, gl_CHECK_NEXT_HEADERS do
+    dnl not work in this situation.
+    AC_EGREP_CPP([vaccine],
+      [#if defined _AIX && !defined __GNUC__
+        AIX vaccine
+       #endif
+      ], [gl_aixcc=yes], [gl_aixcc=no])
+    if test $gl_aixcc = yes; then
+      dnl Provide a substitute <stdarg.h> file.
+      STDARG_H=stdarg.h
+      gl_CHECK_NEXT_HEADERS([stdarg.h])
+      dnl Fallback for the case when <stdarg.h> contains only macro definitions.
+      if test "$gl_cv_next_stdarg_h" = '""'; then
+        gl_cv_next_stdarg_h='"///usr/include/stdarg.h"'
+        NEXT_STDARG_H="$gl_cv_next_stdarg_h"
+      fi
+    else
+      dnl Provide a substitute in <config.h>, either __va_copy or as a simple
+      dnl assignment.
+      gl_CACHE_VAL_SILENT([gl_cv_func___va_copy], [
+        AC_TRY_COMPILE([#include <stdarg.h>], [
+#ifndef __va_copy
+error, bail out
+#endif
+],
+          [gl_cv_func___va_copy=yes], [gl_cv_func___va_copy=no])])
+      if test $gl_cv_func___va_copy = yes; then
+        AC_DEFINE([va_copy], [__va_copy],
+          [Define as a macro for copying va_list variables.])
+      else
+        AH_VERBATIM([gl_VA_COPY], [/* A replacement for va_copy, if needed.  */
+#define gl_va_copy(a,b) ((a) = (b))])
+        AC_DEFINE([va_copy], [gl_va_copy],
+          [Define as a macro for copying va_list variables.])
+      fi
+    fi
+  fi
+])