Fix horizontal label placement.
Fix horizontal label placement.

There were problems when the number of labels was even.

Change-Id: Ia9339bfbde6d60cadccc3a2e447263def98d11c5

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