vtkImagePlaneWidget segfaults with multi-array field data

This issue was created automatically from an original Mantis Issue. Further discussion may take place here.

vtkImagePlaneWidget segfaults on particular types of interaction: pushing (middle mouse button) and edge stretching (middle mouse button + ctrl), when input image data is multi-array field data. If spinning, scaling or rotating is first performed, then no crash occurs with subsequent push/edge drags.