VTK-4697 - resolve full url for use in production and refactor makePreviewImg() function
VTK-4697 - resolve full url for use in production and refactor makePreviewImg() function

vtkio/vtk,vtkio/vtk,vtkio/vtk,vtkio/vtk,vtkio/vtk,vtkio/vtk,vtkio/vtk,vtkio/vtk