ENH: Added StatisticsRelabelImageFilterTest to testing

The itkStatisticsRelabelImageFilterTest1.cxx file has been included in the
/Modules/Filtering/LabelMap/test/CMakeLists.txt so that it can actually be
tested. A fix has been applied to the file since the feature input was not
being set. The necessary test images are also being included. Compiles and
runs fine under Windows 7, Visual Studio 10.

Change-Id: I042c8620e0cc8dde395330924fe53a20b20c724b
Merge topic 'StatisticsRelabelImageFilterCodeCoverage'

d83a3907 ENH: Added StatisticsRelabelImageFilterTest to testing