gdiplus: Implement GdipGet/SetStringFormatMeasurableCharacterRanges.

[Vincent Povirk]

> +    format->character_ranges = GdipAlloc(rangeCount * sizeof(CharacterRange));
> +    if (!format->character_ranges)
> +        return OutOfMemory;
>
> -    return NotImplemented;
> +    memcpy(format->character_ranges, ranges, sizeof(CharacterRange) * rangeCount);
> +    format->range_count = rangeCount;
> +
> +    return Ok;
>  }

Won't this leak memory if I set it twice?

-- 
Vincent Povirk