BUG: Only render legend items that have a label.
BUG: Only render legend items that have a label.

If the label is zero length do not render that plot in the legend.

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