BUG: fixed warnings in TestPolygon.cxx about signed/unsigned comparison
BUG: fixed warnings in TestPolygon.cxx about signed/unsigned comparison

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