Scaling algorithms in Krita Bad (at least at downscaling)

[Bart Coppens]

As said by pippin on #koffice:
<pippin> interpolation is wrong when scaling down, I think I've stated that 
here two or three times,..
<pippin> bilinear uses 4 source pixels/destination pixel, when scaling to 10% 
that means discarding 96% of the image data (using 4 instead of at
<pippin> interpolation only works for filling in data between existing data 
points, the other form of resampling is usually called decimation (though 
that would be the nearest neighbour approach if the word is taken literally)
<pippin> decimation  n : destroying or killing a large part of the population 
(literally every tenth person as chosen by lot)