Log Message:
Update to 2.61:

* Major changes in Autoconf 2.61 (2006-11-17)

** New macros AC_C_FLEXIBLE_ARRAY_MEMBER, AC_C_VARARRAYS.

** AC_ARG_ENABLE and AC_ARG_WITH now allow '.' in feature and package names.

* Major changes in Autoconf 2.60b (2006-10-22)

** BIN_SH
  Autoconf-generated shell scripts no longer export BIN_SH, due to
  configuration hassles with this.  Installers who need BIN_SH in
  their environment should set it before invoking 'configure' and
  'make'.  As far as we know, this affects only Unixware installations.

** Obsolescent macros
  The documentation now says that the following macros are obsolescent,
  as they are superseded by Gnulib:

    AC_FUNC_FNMATCH  AC_FUNC_FNMATCH_GNU  AC_FUNC_GETLOADVG  AC_REPLACE_FNMATCH

  New programs should use the Gnulib counterparts of these macros.
  We have no current plans to remove them from Autoconf.

** AC_COMPUTE_INT no longer caches or reports results.

** AC_CHECK_DECL now also works with aggregate objects.

** AC_USE_SYSTEM_EXTENSIONS now defines _TANDEM_SOURCE for NonStop platforms.

** GNU M4 1.4.7 or later is now recommended.

** m4_mkstemp
  New M4sugar macro, which is more secure than the POSIX M4 maketemp.

** m4_maketemp
  Now an alias for m4_mkstemp.

* Major changes in Autoconf 2.60a (2006-08-25)

** GNU M4 1.4.6 or later is now recommended.

** The check for C99 now tests for varargs macros, as documented.
  It also tests that the preprocessor supports 64-bit integers.

** Autoconf now uses constructs like "#ifdef HAVE_STDLIB_H" rather than
  "#if HAVE_STDLIB_H", so that it now works with "gcc -Wundef \ 
-Werror".

** The functionality of the undocumented _AC_COMPUTE_INT is now provided
  by a public and documented macro, AC_COMPUTE_INT.  The parameters to the
  two macros are different, so autoupdate will not change the old private name
  to the new one.  _AC_COMPUTE_INT may be removed in a future release.

** AC_TYPE_LONG_LONG_INT and AC_TYPE_UNSIGNED_LONG_LONG_INT now require
   that long long types be at least 64 bits wide, as C99 and tradition
   requires.  Formerly, they accepted implementations of any width.