Hi, MatrixTransformMorph
"MatrixTransformMorph is similar to TransformMorph but uses a MatrixTransform2x3 instead of a MorphicTransform. It is used by clients who want use the BalloonEngine for vector-based scaling instead of the standard WarpBlt pixel-based mechanism.” As Ballon is outdated, incomplete and buggy, I think we should just delete this class. https://pharo.fogbugz.com/f/cases/13510/MatrixTransformMorph-is-not-used
