update gettext module

[Bruno Haible]

With the current gettext module, the bison-i18n testdir fails, because
the macro AM_INTL_SUBDIR didn't exist in gettext-0.15. I'm applying this.
The m4/* files have already been updated to gettext-0.16.1 long ago.


2007-03-02  Bruno Haible  <address@hidden>

        * modules/gettext (configure.ac): Require gettext infrastructure
        from version 0.16.1.

--- modules/gettext     1 Feb 2007 01:52:34 -0000       1.16
+++ modules/gettext     3 Mar 2007 02:05:28 -0000
@@ -37,7 +37,7 @@
 
 configure.ac:
 AM_GNU_GETTEXT([external])
-AM_GNU_GETTEXT_VERSION([0.15])
+AM_GNU_GETTEXT_VERSION([0.16.1])
 
 Makefile.am:
 # This is for those projects which use "gettextize --intl" to put a source-code