BUG: Layout strategy needs to be re-initialized when input mtime changes.  Also added a bunch of comments.
BUG: Layout strategy needs to be re-initialized when input mtime changes.  Also added a bunch of comments.

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