[LIBART] sold fills

[Robin Becker <robin jessikat fsnet co uk>]

What is the correct way to get solid fills with libart.

I am using art_rgb_svp_alpha, but even when I set alpha to 255 I get
interpolated colours in the middle of cirles and this leads to horrible
moire effects when large areas are coloured. I deduce that I must be
using the wrong primitive somehow.
-- 
Robin Becker