Added support for Nullable types.

[specimen151]

I got an error when fetching a DateTime? from the database.

        var result = query.ToDocuments();

        var myList = new List<MyType>();
        foreach (var doc in result.Value)
        {
            var dict = doc.Object("vertex").ToObjectDictionary();
            var xxx = dict.ToObject<MyType>();

on the last line there.

I see in the code that this is from a dependency, so I don't know if you want it, but it does solve a problem.

Since I'm not on 3.0 yet, I fixed it on the 2.x branch only.

[yojimbo87]

Thanks a lot, I will update dependency and also 3.x branch from your patch.