COMP: Fix KWSys SharedForward pointer const-ness
COMP: Fix KWSys SharedForward pointer const-ness

This adds const-ness and casts where necessary to avoid pointer
conversion warnings.

hendradarwin/VTK,SimVascular/VTK,daviddoria/PointGraphsPhase1,mspark93/VTK,sumedhasingla/VTK,collects/VTK,aashish24/VTK-old,arnaudgelas/VTK,ashray/VTK-EVM,collects/VTK,Wuteyan/VTK,johnkit/vtk-dev,gram526/VTK,sumedhasingla/VTK,candy7393/VTK,gram526/VTK,aashish24/VTK-old,Wuteyan/VTK,ashray/VTK-EVM,berendkleinhaneveld/VTK,biddisco/VTK,biddisco/VTK,candy7393/VTK,SimVascular/VTK,mspark93/VTK,keithroe/vtkoptix,keithroe/vtkoptix,SimVascular/VTK,cjh1/VTK,Wuteyan/VTK,msmolens/VTK,sankhesh/VTK,jmerkow/VTK,arnaudgelas/VTK,msmolens/VTK,berendkleinhaneveld/VTK,msmolens/VTK,daviddoria/PointGraphsPhase1,collects/VTK,johnkit/vtk-dev,demarle/VTK,johnkit/vtk-dev,mspark93/VTK,Wuteyan/VTK,Wuteyan/VTK,SimVascular/VTK,sankhesh/VTK,candy7393/VTK,keithroe/vtkoptix,jeffbaumes/jeffbaumes-vtk,jeffbaumes/jeffbaumes-vtk,cjh1/VTK,demarle/VTK,biddisco/VTK,sankhesh/VTK,spthaolt/VTK,sankhesh/VTK,gram526/VTK,biddisco/VTK,aashish24/VTK-old,arnaudgelas/VTK,candy7393/VTK,gram526/VTK,cjh1/VTK,jmerkow/VTK,arnaudgelas/VTK,msmolens/VTK,SimVascular/VTK,jeffbaumes/jeffbaumes-vtk,johnkit/vtk-dev,demarle/VTK,collects/VTK,candy7393/VTK,mspark93/VTK,berendkleinhaneveld/VTK,daviddoria/PointGraphsPhase1,berendkleinhaneveld/VTK,berendkleinhaneveld/VTK,sankhesh/VTK,ashray/VTK-EVM,naucoin/VTKSlicerWidgets,jmerkow/VTK,daviddoria/PointGraphsPhase1,Wuteyan/VTK,mspark93/VTK,msmolens/VTK,gram526/VTK,msmolens/VTK,keithroe/vtkoptix,naucoin/VTKSlicerWidgets,cjh1/VTK,aashish24/VTK-old,jmerkow/VTK,hendradarwin/VTK,sumedhasingla/VTK,spthaolt/VTK,gram526/VTK,collects/VTK,ashray/VTK-EVM,jeffbaumes/jeffbaumes-vtk,sumedhasingla/VTK,gram526/VTK,spthaolt/VTK,sankhesh/VTK,biddisco/VTK,spthaolt/VTK,cjh1/VTK,ashray/VTK-EVM,hendradarwin/VTK,jmerkow/VTK,spthaolt/VTK,naucoin/VTKSlicerWidgets,naucoin/VTKSlicerWidgets,cjh1/VTK,spthaolt/VTK,SimVascular/VTK,jeffbaumes/jeffbaumes-vtk,sumedhasingla/VTK,demarle/VTK,keithroe/vtkoptix,jmerkow/VTK,ashray/VTK-EVM,daviddoria/PointGraphsPhase1,ashray/VTK-EVM,sankhesh/VTK,jmerkow/VTK,spthaolt/VTK,mspark93/VTK,SimVascular/VTK,aashish24/VTK-old,hendradarwin/VTK,johnkit/vtk-dev,sumedhasingla/VTK,berendkleinhaneveld/VTK,biddisco/VTK,sumedhasingla/VTK,hendradarwin/VTK,jeffbaumes/jeffbaumes-vtk,mspark93/VTK,gram526/VTK,johnkit/vtk-dev,aashish24/VTK-old,sankhesh/VTK,ashray/VTK-EVM,msmolens/VTK,hendradarwin/VTK,candy7393/VTK,johnkit/vtk-dev,mspark93/VTK,keithroe/vtkoptix,candy7393/VTK,hendradarwin/VTK,demarle/VTK,keithroe/vtkoptix,demarle/VTK,demarle/VTK,candy7393/VTK,jmerkow/VTK,naucoin/VTKSlicerWidgets,naucoin/VTKSlicerWidgets,biddisco/VTK,berendkleinhaneveld/VTK,Wuteyan/VTK,arnaudgelas/VTK,collects/VTK,sumedhasingla/VTK,msmolens/VTK,daviddoria/PointGraphsPhase1,keithroe/vtkoptix,SimVascular/VTK,demarle/VTK,arnaudgelas/VTK