Adding support for Tuple<T1, T2, ...> as option/value parsing target

**Issue by [gsscoder](https://github.com/gsscoder)**
_Sunday Jul 05, 2015 at 15:59 GMT_
_Originally opened as https://github.com/gsscoder/commandline/issues/182_

----

I want to be able to parse this:

``` bash
$ app --webserver localhost 8080
```

to:

``` csharp
class Options {
[Option] public Tuple WebServer { get; set; }
}
```

Opinions? cc/ @mizipzor @nemec @gimmemoore