ENH: Add display of direction vectors of image's IJK to Slicer's RAS coordinate.

Contributed by Kevin Wang

See #2869 - http://na-mic.org/Mantis/view.php?id=2869

From: kevin Wang <kevin.wang@rmp.uhn.ca>

git-svn-id: http://svn.slicer.org/Slicer4/trunk@21711 3bd1e089-480b-0410-8dfb-8563597acbee