ENH: Update EMSegment to add autoBoundaryDetection for command line module

This commit adds the option "autoBoundaryDetection" to EMSegmentCommandLine
If flag is set then the method will automatically determine the boundary
box which includes non-zero voxels in the input images. This speed things
up when working with skull stripped images. (See EMSegment r17112)

git-svn-id: http://svn.slicer.org/Slicer4/trunk@24774 3bd1e089-480b-0410-8dfb-8563597acbee