ENH: Separate the notion of a request for LFS and its availability.  Allow user code to block definitions of LFS macros.  Added framework to give error if sys/types.h is included before this header when LFS is requested (currently disabled).
ENH: Separate the notion of a request for LFS and its availability.  Allow user code to block definitions of LFS macros.  Added framework to give error if sys/types.h is included before this header when LFS is requested (currently disabled).

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