(split) ENH: ITK legacy and compatibility.
(split) ENH: ITK legacy and compatibility.

ITKApps needs ITK to be configured with ITK_LEGACY_REMOVE OFF and
ITKV3_COMPATIBILITY ON.

Change-Id: I2f19bc5e4c9f0581c79b90fe41a60cdd7101cdb7

aylward/ImageViewer,thewtex/ImageViewer,KitwareMedical/ImageViewer