ENH: If the appended data section is encoded, the file format will be valid XML.  Writer now writes the <?xml version="1.0"?> XML header at the top in this case.  Also fixed crash on empty input.
ENH: If the appended data section is encoded, the file format will be valid XML.  Writer now writes the <?xml version="1.0"?> XML header at the top in this case.  Also fixed crash on empty input.

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