Allow better font rendering for projects like Koffice

https://bugs.kde.org/show_bug.cgi?id=237305

Koffice fonts currently looks ugly.

http://habreffect.ru/files/7d9/4e2deaef0/koffice-fonts.png

That's because Qt uses a strategy of font rendering that doesn't care for font metrics. I propose that it be possible to use a different method of font rasterization with Qt where the measurements do matter a lot, like KDE's Koffice and Okular.

This version of font rasterization would be ideal:

http://www.antigrain.com/research/font_rasterization/

It's a very interesting article, and, seeing as it's three years old now, I can't see why no one implemented it anywhere, since the algorithms described are even patent-free.

This is what Koffice should be able to achieve with Qt:

http://www.antigrain.com/research/font_rasterization/text_ft_antigrain.png

And here is a sample program, which implies that this was possible even three years ago:

http://www.antigrain.com/research/font_rasterization/truetype_test_02_ft.zip

You need wine to run it, or alternatively the author states it can be compiled for Linux with a bit of tweaking.