BUG: ImagePlaneWidget TextureVisibility
BUG: ImagePlaneWidget TextureVisibility

Only turn on texture if TextureVisibility is true AND ImageData is
not null. Otherwise, OpenGLPolyDataMapper will crash.

keithroe/vtkoptix,keithroe/vtkoptix,SimVascular/VTK,keithroe/vtkoptix,SimVascular/VTK,SimVascular/VTK,SimVascular/VTK,SimVascular/VTK,keithroe/vtkoptix,keithroe/vtkoptix,keithroe/vtkoptix,SimVascular/VTK,SimVascular/VTK,keithroe/vtkoptix,keithroe/vtkoptix,SimVascular/VTK