Namespace name has to be explicitly used for QML compatibility

If a class is declared inside a namespace, then the namespace name has to be included when referencing to the class in Q_PROPERTY declarations and in associated read and write function prototypes and, also, in Q_INVOKABLE function prototypes. For example, let's consider two classes Bar and Baz that are declared in namespace Foo:

namespace Foo {

    class Baz : public QObject
    {
        ...
    };

    class Bar : public QObject
    {
        Q_OBJECT
        Q_PROPERTY(Foo::Baz* baz READ baz CONSTANT)
//        Q_PROPERTY(Baz* baz READ baz CONSTANT)
    public:
        ...
        Foo::Bar* baz() const;
//        Bar* baz() const;
        Q_INVOKABLE Foo::Bar* getBaz() const;
//        Q_INVOKABLE Bar* getBaz() const;
        ...
    };

} /* namespace Foo */

As mentioned above, the namespace names in front of class name Baz are necessary for the classes to be usable in QML code. If the namespace names are removed from the declaration of class Bar (commented lines), the QML code using the classes does not work as expected. See the attached application for an example. In general, C++ does not have this kind of limitation; it is enough that the class declarations are inside the namespace and there is no need to use namespace names. The suggestion is that the QML documentation is updated so that this issue is made clearer for the reader. It would help developers who use namespaces and encounter "not-an-object" error messages.