ENH: 2487. Added new method: void vtkMRMLHierarchyNode::MoveInParent(int increment)
Added tests for this method in vtkMRMLHierarchyNodeTest3.

git-svn-id: http://svn.slicer.org/Slicer4/trunk@22263 3bd1e089-480b-0410-8dfb-8563597acbee