To be able to read volumes(slicer:0x263f5c0#vtkMRMLScalarVolumeNode1), the
CLI modules need to load MRMLImageIOPlugin, it is done automatically by ITK
by scanning plugins in the directory retrieved from the environment
variable ITK_AUTOLOAD_PATH.

git-svn-id: http://svn.slicer.org/Slicer4/trunk@14853 3bd1e089-480b-0410-8dfb-8563597acbee