Define NiBSplineTransformInterpolator and unknown for NiBSplineData.

include/obj/NiBSplineCompTransformInterpolator.h

include/obj/NiBSplineData.h

include/obj/NiBSplineTransformInterpolator.h

src/obj/NiBSplineCompFloatInterpolator.cpp

src/obj/NiBSplineCompTransformInterpolator.cpp

src/obj/NiBSplineData.cpp

src/obj/NiBSplineTransformInterpolator.cpp