COMP: Specify std:: prefix for pow
COMP: Specify std:: prefix for pow

To address:

/FdWrapping\Modules\MorphologicalContourInterpolation\CMakeFiles\MorphologicalContourInterpolationPython.dir\ -c Wrapping\Modules\MorphologicalContourInterpolation\itkMorphologicalContourInterpolatorPython.cpp
c:\projects\itkmorphologicalcontourinterpolation\include\itkMorphologicalContourInterpolator.hxx(149) : error C2668: 'pow' : ambiguous call to overloaded function

KitwareMedical/MorphologicalContourInterpolation,thewtex/MorphologicalContourInterpolation,dzenanz/MorphologicalContourInterpolation,thewtex/MorphologicalContourInterpolation,KitwareMedical/MorphologicalContourInterpolation,KitwareMedical/ITKMorphologicalContourInterpolation,KitwareMedical/ITKMorphologicalContourInterpolation,dzenanz/MorphologicalContourInterpolation