ENH: expose bounding box label statistic

A separate member/measurement variable is added to the
LabelStatisticsImageFiter, which store the Bounding box as an array
just the ITK, although as a int not a unsigned long or what ever ITK
is configured for.

Change-Id: I78270536f9ce2472f3c4f8daf6a69e9bfecfd488
ENH: adding test for bounding box in label statistics

Change-Id: I27a1ee3546a762f28c84dd27487cb7d30b8d6343
BUG: Fix consistency of TransformTest.ReadTransformResample

Switched to from default linear to explicit nearest neighborhood
interpolator to make hash consistent across platforms.

Change-Id: I67e5e4398301e0c902afe63eb61abb6efe6943b3
BUG: Fix double image from py3 true division

This example was failing due to a mixture of float and double image.

The result of the true division operator on images in SimpleITK is a
double image. We import the true division as the standard operator,
then convert the result back to the expected.

Change-Id: Ie23c178657405944f7f013c0e9663f1b708a573f
Merge topic 'AddBoundingBoxToLabelStatistics'

f2fe063 ENH: adding test for bounding box in label statistics
4ce7ab2 ENH: expose bounding box label statistic
Merge topic 'UseNearestNeighborReadTransformTest'

5f3cb26 BUG: Fix consistency of TransformTest.ReadTransformResample
Merge topic 'FixPy32FFTConvolutionExample'

cd90498 BUG: Fix double image from py3 true division