BUG: Handle case when select() lies
BUG: Handle case when select() lies

According to "man select" on Linux it is possible that select() lies
about data being ready on a pipe in some subtle cases.  We deal with
this by switching to non-blocking i/o and checking for EAGAIN.  See
issue #7180.

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