* configure.ac: Do nor require libiconv for W32.
* common/utf8conv.c [W32]: Do not incluce iconv.h. Request
libgpg-error iconv macros.
(jnlib_iconv): Use ICONV_CONST macro.
* build-aux/speedo/w32/inst.nsi [!WITH_GUI]: Do not install libiconv.
* build-aux/speedo.mk (speedo_spkgs) [!WITH_GUI]: Likewise.
Signed-off-by: Werner Koch <wk@gnupg.org>