Added third test and found out why this bug was so well hidden so far: If a new vtkMatrix4x4 is created, it is set to identity. So when TransferItkTransformToVtkMatrix was used on a newly created matrix before this bugfix it was still ok.

However, if there were some elements in the last row previous to this bugfix, they would incorrectly still have remained. Changed tests to account for this by getting some values into the matrix before applying TransferItkTransformToVtkMatrix.