Should not wrap Type instances as TypeReference by default

[lahma]

I couldn't find a reason why we would want to convert Type instances to TypeReference instances unless it's explicit need for type construction (importNamespace, explicit TypeReference.Create). With this change can now read values like a.GetType().FullName, earlier it was hidden as TypeRefereence which doesn't expose much. Old behavior can still be achieved by engine type mappers / object converters.

The README shows correct ways to achieve this:

and then to assign local namespaces the same way System does it for you, use importNamespace

jint> var Foo = importNamespace('Foo');
jint> var bar = new Foo.Bar();
jint> log(bar.ToString());

adding a specific CLR type reference can be done like this

engine.SetValue("TheType", TypeReference.CreateTypeReference(engine, typeof(TheType)))

But there's unit test cases that relies on auto-wrapping:

 _engine.SetValue("TestStruct", typeof(TestStruct));

So I kept the auto-wrapping when called via engine.SetValue(name, type), but no longer automatic in JsValue.FromObject.

fixes #533

[sebastienros]

I'll trust your judgement because this is maybe some of the oldest code that is still remaining.