Boutell backport AA from PHP

Not really new, but I did not read the GD site that much :)
In GD 2.0.26 (Changelog), they backport my antialiasing function introduced in php 4.3:
„Drastically faster, less memory-intensive antialiased drawing, thanks to Pierre-Alain Joye. This code was imported from the PHP ‚fork‘ of gd.“
They should backport the ellipse and filling functions I rewrote for php.