Update list of M4 macros

As an alternative, we could avoid shipping all the gettext macros and
require developpers have gettext if they want to rebuild ./configure
from a source tarball. I'd tend to lean for this option.

m4/Makefile.am

@@ -2,12 +2,16 @@ NULL =
 
 EXTRA_DIST = \
 	codeset.m4 \
+	flags.m4 \
 	gettext.m4 \
 	glibc21.m4 \
+	glibc2.m4 \
 	iconv.m4 \
 	intdiv0.m4 \
 	intl.m4 \
 	intldir.m4 \
+	intlmacosx.m4 \
+	intmax.m4 \
 	inttypes-pri.m4 \
 	inttypes_h.m4 \
 	lcmessage.m4 \
@@ -15,13 +19,19 @@ EXTRA_DIST = \
 	lib-link.m4 \
 	lib-prefix.m4 \
 	lock.m4 \
+	longlong.m4 \
+	nls.m4 \
+	po.m4 \
+	printf-posix.m4 \
 	private.m4 \
 	progtest.m4 \
+	size_max.m4 \
 	stdint_h.m4 \
 	uintmax_t.m4 \
-	ulonglong.m4 \
 	visibility.m4 \
 	vlc.m4 \
-	flags.m4 \
+	wchar_t.m4 \
+	wint_t.m4 \
+	xsize.m4 \
 	$(NULL)