BUGFIX: Allocate AMR cache in vtkAMRBaseReader
BUGFIX: Allocate AMR cache in vtkAMRBaseReader

Fixed segfault due to accessing the amrCache which was
not allocated. Now, amrCache is properly allocated in
vtkAMRBaseReader::Initialize()

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