[Paraview] OpenGL Backend Identification

[Ben Boeckel]

On Thu, Dec 10, 2015 at 10:08:14 -0500, David E DeMarle wrote:
> And it should appear in a wrapped class so that we can get it at runtime
> from python.

In that case, there should probably be an enum in RenderingCore:

    enum vtkRenderingBackend {
        ...
    };

    class vtkRenderingSomething {
        static vtkRenderingBackend getRenderingBackend();
    };

--Ben