DataMapperAttributeResolverTask does not run Setup method on the resolved data mapper

[Krusen]

As the title says the Setup() method is not invoked on the resolved data mapper when using the DataMapperAttribute to specify a data mapper directly on a property.

This causes AbstractDataMapper.Configuration property to never be set, which results in NullReferenceExceptions in most cases.

[mikeedwards83]

Can you give me an example of a model with the DataMapperAttribute?

[Krusen]

public class StubClass
{
    [DataMapper(typeof(StubMapper))]
    public string StubMapperProperty { get; set; }
}

public class StubMapper : AbstractDataMapper
{
    // This is not invoked
    public override void Setup(DataMapperResolverArgs args)
    {
        base.Setup(args);
    }
}

It should also be pretty clear from the PR #381 with the new unit test.