BUG: Fix out of bounds access for image region size

This patch was detected by the following warning:
/.../SimpleITK-build/ITK-prefix/include/ITK-4.6/itkSize.h: In member
function 'void itk::LabelVotingImageFilter<TInputImage,
TOutputImage>::ThreadedGenerateData(const typename
itk::ImageToImageFilter<TInputImage,
TOutputImage>::OutputImageRegionType&, itk::ThreadIdType) [with
TInputImage = itk::Image<long unsigned int, 3u>, TOutputImage =
itk::Image<long unsigned int, 3u>]':
 /.../SimpleITK-build/ITK-prefix/include/ITK-4.6/itkSize.h:159:
 warning: array subscript is above array bounds

Change-Id: I474492d0654ed91844fac9851877907b41be534a
BUG: Add export specification to DCMTKFileReader and utilities

Change-Id: I1ccd7d9a95cf8005abbc0b725bb4daabe891822e
Merge topic 'AddDCMTKFileReaderExportSpecification'

d34bfa4f BUG: Add export specification to DCMTKFileReader and utilities
Merge topic 'FixArrayBoundsForLabelVoting'

4030325b BUG: Fix out of bounds access for image region size