[ft] ftview and ftdiff doesn't support unicode

[Алексей Подтележников]

Dear freetypers,

IMHO, the weakest part of freetype is its rendering quality on
international desktop.
Accents, umlauts, rings, etc all distort the glyphs. Unfortunately,
these are even hard to demontrate because ftview and ftdiff do not
support unicode. Only ftstring does. I would like to implement unicode
support in all appropriate ft2demos.

I have looked at porting ftstring code to ftview,  but unicode
interpretation is not implemented as a separate function. Would such
function belong to ftcommon.c? I assume that freetype itself does not
need such function.

Thanks,
Alexei