Greater DataContractSerializer compatibility

[AArnott]

no existing resolver can simulate DataContractSerializer.
ex:

[DataContract]
public class Master {
    [DataMember]
    public string A { get; set; }
    [DataMember]
    internal Detail B { get; set; }
}
public class Detail {
    public string B1 { get; set; }
    internal string B2 { get; set; }
}

The original DataContractSerializer, includes A, B and B1.
The ContractlessStandardResolver only includes A.
The ContractlessStandardResolverAllowPrivate, include A, B and B1 and B2.

Originally posted by @fredliex in #18 (comment)

[AArnott]

I'm working on a test to repro this.

[peterwald]

It would be very helpful if we can also handle internal [DataContract] classes with internal [DataMember] properties as well.

[DataContract]
internal class Master {
    [DataMember]
    internal string A { get; set; }
    [IgnoreDataMember]
    internal string B { get; set; }
}

[AArnott]

Internal classes might work, depending on the real outcome of MessagePack-CSharp#88

[AArnott]

If this isn't already working in 2.0, please open a new issue on the root project (not my fork).