Ability to use Object/Tuple as Option

Thanks for this awesome library!

Is there any possibility to to something like this:

```csharp
[Option('p', "position", Required = true, HelpText = "This will be cool")]
public object Position{ get; set; }
```

console:
```set-position -p {1,1,1}```

of course `Position` can be a typed object as well or maybe a tuple...
What do you think?