Add new auxiliary 'ar-lib' script, wrapping Microsoft lib. * lib/ar-lib: New auxiliary script. * lib/Makefile.am: Add above. * tests/ar-lib.test: New test. * tests/Makefile.am: Add above. * automake.in (@common_files): Distribute the 'ar-lib' script. * doc/automake.texi (Auxiliary Programs): Mention the new 'ar-lib' script. (Optional): Mention 'ar-lib' in AC_CONFIG_AUX_DIR. * NEWS: Update. Signed-off-by: Ralf Wildenhues <Ralf.Wildenhues@gmx.de>