gpaint switch to kolourpaint

[David Van Assche]

A couple of us have been comparing gpaint and kolourpaint4, and the
latter is a far better choice, resembling pbrush a little more closely
and seeming to run more stable. I'd like to propose, therefore,
changing the seed to contain kolourpaint4 instead of gpaint. It is
already in main so this should not be a problem.
Whatchall think?

kind Regards,
David Van Assche
www.nubae.com