ENH: Added Allocate() method to the API
ENH: Added Allocate() method to the API

Added method to actually allocate the internal visibility
array on-demand.

Change-Id: If8bee5e64c961d6e2707d8b1c91bb6b4bdf4cf97

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