ENH: Deprecate ::Zero and ::One
These were deprecated in 2012; just before the ITK 4.2 release. ZeroValue() and OneValue() should be used instead.
-- This coforms to ITKv4 changes made in 6c23e1daace315a40831cf255b2af57df5d3505c 3f712cd09551e3c80d8beac8a7a097b8bfc73862
When building with clang on 10.9 where ITKv4 is a shared library, a linking error occured for unfound symbols: NumericTraits< OutputPixelType >::Zero but using the NumericTraits< OutputPixelType >::ZeroValue() allows linkage to occur properly.