intl: Don't export symbols from static MSVC .obj files.
* gettext-runtime/intl/configure.ac (WOE32DLL): Set to 1 or 0, not 'yes' or
'no'. Don't define as C macro any more.
(DLL_VARIABLE): Test DLL_EXPORT, not _DLL.
* gettext-runtime/intl/export.h: Use the value of WOE32DLL at configure time.
Set LIBINTL_DLL_EXPORTED to empty on MSVC when DLL_EXPORT is not defined.
* gettext-runtime/intl/Makefile.am (libgnuintl.h): Substitute the value of
@WOE32DLL@.
* gettext-runtime/intl/intl-compat.c (DLL_EXPORTED): Set to empty on MSVC when
DLL_EXPORT is not defined.
* gettext-runtime/intl/printf.c (DLL_EXPORTED): Likewise.
* gettext-runtime/intl/setlocale.c (DLL_EXPORTED): Likewise.
