BUGFIX: Correct linear cell index calcuation
BUGFIX: Correct linear cell index calcuation

Corrected linear cell index calculation in particular
for support of all three axis-aligned planes.

candy7393/VTK,mspark93/VTK,ashray/VTK-EVM,hendradarwin/VTK,cjh1/VTK,candy7393/VTK,mspark93/VTK,biddisco/VTK,hendradarwin/VTK,sumedhasingla/VTK,sankhesh/VTK,mspark93/VTK,ashray/VTK-EVM,msmolens/VTK,gram526/VTK,demarle/VTK,demarle/VTK,keithroe/vtkoptix,hendradarwin/VTK,gram526/VTK,johnkit/vtk-dev,biddisco/VTK,aashish24/VTK-old,gram526/VTK,SimVascular/VTK,SimVascular/VTK,sankhesh/VTK,SimVascular/VTK,gram526/VTK,collects/VTK,demarle/VTK,mspark93/VTK,msmolens/VTK,aashish24/VTK-old,sankhesh/VTK,berendkleinhaneveld/VTK,keithroe/vtkoptix,collects/VTK,hendradarwin/VTK,ashray/VTK-EVM,aashish24/VTK-old,sankhesh/VTK,berendkleinhaneveld/VTK,berendkleinhaneveld/VTK,ashray/VTK-EVM,cjh1/VTK,cjh1/VTK,demarle/VTK,demarle/VTK,jmerkow/VTK,msmolens/VTK,sumedhasingla/VTK,sumedhasingla/VTK,sumedhasingla/VTK,aashish24/VTK-old,msmolens/VTK,candy7393/VTK,gram526/VTK,ashray/VTK-EVM,mspark93/VTK,gram526/VTK,biddisco/VTK,candy7393/VTK,jmerkow/VTK,collects/VTK,mspark93/VTK,keithroe/vtkoptix,jmerkow/VTK,collects/VTK,cjh1/VTK,johnkit/vtk-dev,hendradarwin/VTK,candy7393/VTK,berendkleinhaneveld/VTK,johnkit/vtk-dev,keithroe/vtkoptix,berendkleinhaneveld/VTK,ashray/VTK-EVM,aashish24/VTK-old,SimVascular/VTK,keithroe/vtkoptix,cjh1/VTK,johnkit/vtk-dev,sumedhasingla/VTK,demarle/VTK,keithroe/vtkoptix,gram526/VTK,berendkleinhaneveld/VTK,ashray/VTK-EVM,msmolens/VTK,mspark93/VTK,sankhesh/VTK,collects/VTK,msmolens/VTK,ashray/VTK-EVM,biddisco/VTK,hendradarwin/VTK,keithroe/vtkoptix,sumedhasingla/VTK,johnkit/vtk-dev,SimVascular/VTK,berendkleinhaneveld/VTK,sumedhasingla/VTK,mspark93/VTK,demarle/VTK,SimVascular/VTK,biddisco/VTK,SimVascular/VTK,jmerkow/VTK,biddisco/VTK,hendradarwin/VTK,msmolens/VTK,jmerkow/VTK,sankhesh/VTK,gram526/VTK,sankhesh/VTK,sumedhasingla/VTK,jmerkow/VTK,msmolens/VTK,SimVascular/VTK,johnkit/vtk-dev,candy7393/VTK,jmerkow/VTK,candy7393/VTK,johnkit/vtk-dev,cjh1/VTK,biddisco/VTK,sankhesh/VTK,keithroe/vtkoptix,collects/VTK,candy7393/VTK,jmerkow/VTK,demarle/VTK,aashish24/VTK-old