Importing LabelStatistic Module from Slicer

This is the original LabelStatistics module from Slicer3D by Steve
Pieper. This is the basis for the ITK/SimpleITK based module.
Changes to use SimpleITK StatisticsImageFilter
Adding statistics from LabelShapeStatistics

Additional changes were made so that the behavior of the widgets would
be robust to missing keys for labels, and value of types not
convertible to float.
Add additional robustness to ignore statistics of non-float type
The items in the label statistics table should not be edit-able
Import sitkUtils
Remove statistics slicelet
Adding basic Widget test which currently has an issue creating the
modual's widget.
Adding basic testing for the logic class

Added early return to widget test to by pass module registration
issue.
Merge branch 'LabelObjectStatistics'