DOC:  Remove documentation that is not relevant to VTK6
DOC:  Remove documentation that is not relevant to VTK6

This readme file does not work for VTK6 and is very confusing.

Change-Id: If4b03ae5b5bfe03c488a11c1519c0b2f9dfa4374

msmolens/VTK,demarle/VTK,SimVascular/VTK,jmerkow/VTK,hendradarwin/VTK,johnkit/vtk-dev,sumedhasingla/VTK,keithroe/vtkoptix,gram526/VTK,demarle/VTK,sumedhasingla/VTK,sankhesh/VTK,mspark93/VTK,msmolens/VTK,ashray/VTK-EVM,SimVascular/VTK,candy7393/VTK,jmerkow/VTK,demarle/VTK,jmerkow/VTK,msmolens/VTK,keithroe/vtkoptix,jmerkow/VTK,johnkit/vtk-dev,johnkit/vtk-dev,mspark93/VTK,sumedhasingla/VTK,gram526/VTK,gram526/VTK,keithroe/vtkoptix,sankhesh/VTK,mspark93/VTK,jmerkow/VTK,sumedhasingla/VTK,keithroe/vtkoptix,sumedhasingla/VTK,candy7393/VTK,mspark93/VTK,msmolens/VTK,gram526/VTK,sumedhasingla/VTK,candy7393/VTK,mspark93/VTK,ashray/VTK-EVM,gram526/VTK,keithroe/vtkoptix,ashray/VTK-EVM,mspark93/VTK,sumedhasingla/VTK,gram526/VTK,candy7393/VTK,mspark93/VTK,sankhesh/VTK,gram526/VTK,keithroe/vtkoptix,ashray/VTK-EVM,SimVascular/VTK,keithroe/vtkoptix,candy7393/VTK,demarle/VTK,jmerkow/VTK,SimVascular/VTK,candy7393/VTK,hendradarwin/VTK,hendradarwin/VTK,sankhesh/VTK,johnkit/vtk-dev,demarle/VTK,johnkit/vtk-dev,SimVascular/VTK,demarle/VTK,SimVascular/VTK,hendradarwin/VTK,gram526/VTK,johnkit/vtk-dev,demarle/VTK,SimVascular/VTK,jmerkow/VTK,msmolens/VTK,keithroe/vtkoptix,ashray/VTK-EVM,demarle/VTK,hendradarwin/VTK,ashray/VTK-EVM,SimVascular/VTK,sankhesh/VTK,sumedhasingla/VTK,msmolens/VTK,msmolens/VTK,ashray/VTK-EVM,candy7393/VTK,mspark93/VTK,candy7393/VTK,hendradarwin/VTK,sankhesh/VTK,sankhesh/VTK,msmolens/VTK,sankhesh/VTK,hendradarwin/VTK,johnkit/vtk-dev,ashray/VTK-EVM,jmerkow/VTK