gdi32: Try Fontconfig substitutions when the font face is missing.

gdi32: Try Fontconfig substitutions when the font face is missing.

This improves font selection. With this patch, we can choose a decent
font family by Fontconfig.

Otherwise, Wine chooses some fonts based on supported charset, e.g. Droid
Sans Fallback. Droid Sans Fallback supports various scripts including
Japanese. However, as it's a fallback font, it doesn't have Latin alphabet
glyphs. If the font is chosen, typically Japanese Ubuntu environment, users
see a lot of squares instead of Latin alphabets.

This patch asks Fontconfig for the best font for the current locale. If the
font is returned and matches requested charset, the font is used. If failure,
it fallbacks to existing procedure.

Signed-off-by: Akihiro Sagawa <sagawa.aki@gmail.com>
Signed-off-by: Huw Davies <huw@codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>