This condition applies a scalar multiplier to the value of another
boundary condition.

Usage
    Property     | Description             | Required    | Default value
    scale        | Time varing scale       | yes         |
    patch        | patchField providing the raw patch value | yes |

Example of the boundary condition specification to scale a reference
velocity of (15 0 0)  supplied as a fixedValue by a table of values
that ramps the scale from 0 to 1 over 1 second:

    <patchName>
    {
        type            scaledFixedValue;

        scale table
        (
            (    0   0)
            (  1.0 1.0)
            (100.0 1.0)
        );

        patch
        {
            type            fixedValue;
            value           uniform (15 0 0);
        }
    }