Add optional arguments for the ViewOptions constructor, such that a
developer can use named arguments for cleaner code.

This is an example of how you would do it before:

    var options = new ViewOptions();
    options.Group = true;
    options.StartKey.Add("Belgium");
    options.EndKey.Add("France");
    var results = db.View<Country>("countries", options);

This is how you could do it now:

    var results = db.View<Country>("countries",
        new ViewOptions(
            group: true,
            startKey: new KeyOptions("Belgium"),
            endKey: new KeyOptions("France")
        ));