qdoc: qdoc was confused by namespace and module with same name

When qdoc searched for QtConncurrent::blockingFilter(),
it found the module node for QtConcurrent instead of the
namespace. This was because qdoc wasn't given specific
enough instructions on how to perform the search. Now
it searches for the namespace first, then the C++ class,
then the module.

Task-number: QTBUG-31535
Change-Id: I4f8aec503903508789738f2a77c76f47a3e80a93
Reviewed-by: Jerome Pasion <jerome.pasion@digia.com>
doc: QOpenGLFramebufferObject::bindDefault() was marked internal

The \internal was removed.

Task-number: QTBUG-31645
Change-Id: I98b57ec3816b6d9c49e3488accb65f147aeb15f1
Reviewed-by: Jerome Pasion <jerome.pasion@digia.com>