cellCoBlended: New surfaceInterpolation scheme based on CoBlended using the cell-based Courant number

    This scheme is equivalent to the CoBlended scheme except that the Courant
    number is evaluated for cells using the same approach as use in the
    finite-volume solvers and then interpolated to the faces rather than being
    estimated directly at the faces based on the flux.  This is a more
    consistent method for evaluating the Courant number but suffers from the
    need to interpolate which introduces a degree of freedom.  However, the
    interpolation scheme for "Co" is run-time selected and may be specified in
    "interpolationSchemes" and "localMax" might be most appropriate.

    Example of the cellCoBlended scheme specification using LUST for Courant
    numbers less than 1 and linearUpwind for Courant numbers greater than 10:
    \verbatim
    divSchemes
    {
        .
        .
        div(phi,U)  Gauss cellCoBlended 1 LUST grad(U) 10 linearUpwind grad(U);
        .
        .
    }

    interpolationSchemes
    {
        .
        .
        interpolate(Co) localMax;
        .
        .
    }
    \endverbatim