BUG: LabelGeometry cropped images with non-unit spacing incorrectly

The itkLabelGeometryImageFilter previously cropped object images
incorrectly when the input image had non-unit spacing.  This was
corrected by simply including spacing in the resampler.  This patch
also includes a rewritten test that is simpler and clearer.  The test
now includes image regression tests.  It also includes feature values
regression tests by writing and reading the features values as CSV
files.  It tests both 2D images and 3D volumes.

Change-Id: I6767489993b30c187ae41b3a6c904bc3dd68d67e
Merge topic 'LabelGeometryImageFilter'

f2052c8 BUG: LabelGeometry cropped images with non-unit spacing incorrectly