improved VTK version parsing
improved VTK version parsing

carolFrohlich/nipype,mick-d/nipype,sgiavasis/nipype,carolFrohlich/nipype,sgiavasis/nipype,FCP-INDI/nipype,carolFrohlich/nipype,FCP-INDI/nipype,mick-d/nipype,mick-d/nipype,sgiavasis/nipype,FCP-INDI/nipype,FCP-INDI/nipype,mick-d/nipype,sgiavasis/nipype,carolFrohlich/nipype