Imagick::getImageChannelStatistics() is not great

[Danack]

It seems to be returning too many arrays of info, and it's not clear which entries are meant to be used.

The test tests/031_Imagick_affineTransformImage_basic.phpt is currently failing, because that has confused me.

Someone needs to dig into the ImageMagick code to see what is happening, and then probably only populate the arrays entries that make sense.