BUG: update link to LiverData.mrb

Fixed the scene file to show the model hierarchies and uploaded
a new mrb file to midas at 
http://slicer.kitware.com/midas3/download?items=117033

Issue #3469



git-svn-id: http://svn.slicer.org/Slicer4/trunk@22659 3bd1e089-480b-0410-8dfb-8563597acbee