BUG: niral_utilities dependency was building too many tool by default.

Only DTI and DTI related tools are now built. This includes:
-PolyDataMerge
-PolyDataTransform
-CropDTI (CropTools)
ENH: Update niral_utilities to build it with ITKv4.6
COMP: explicitly include UseGenerateCLP.cmake
ENH: Prepare for future deprecated ITK features

vim $(echo $(git grep -l "::One\>") $(git grep -l "::Zero\>") $(git grep
    -l "( *void *) *;")|sort -u )

:%s/::One\>/::OneValue()/ge
:%s/::Zero\>/::ZeroValue()/ge
:%s/( *void *) *;/();/ge
:%s/( *void *) *ITK_OVERRIDE *;/() ITK_OVERRIDE;/ge
:%s/( *void *) *const *ITK_OVERRIDE *;/() const ITK_OVERRIDE;/ge