added support for having no DISPLAY
added support for having no DISPLAY

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