STYLE: Add comments for Floor() and Ceil() implementations.
STYLE: Add comments for Floor() and Ceil() implementations.

Change-Id: Idb33d5457df758b4c20e1b706b5755c9490ba1b6

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