ENH: createPatch: allow duplicating face (for ACMI)

    // Example of creating cyclicACMI patch pair
    // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    // (creates duplicate faces for blockage)
    {
        // Name of new patch
        name left_couple;

        // Dictionary to construct new patch from
        patchInfo
        {
            type cyclicACMI;
            neighbourPatch right_couple;
            nonOverlapPatch left_blockage;
        }

        // Select faces
        constructFrom set;
        set left_faces_set;
    }

    {
        name left_blockage;
        patchInfo
        {
            type    wall;
        }

        // Select faces
        constructFrom set;
        set left_faces_set;
    }

    {
        // Name of new patch
        name right_couple;

        // Dictionary to construct new patch from
        patchInfo
        {
            type cyclicACMI;
            neighbourPatch left_couple;
            nonOverlapPatch right_blockage;
        }

        // Select faces
        constructFrom set;
        set right_faces_set;
    }

    {
        name right_blockage;
        // Dictionary to construct new patch from
        patchInfo
        {
            type    wall;
        }

        // Select faces
        constructFrom set;
        set right_faces_set;
    }