qdoc: Don't include inherited members in the class ref

qdoc: Don't include inherited members in the class ref

Once upon a time, the inherited functions, signals,
slots, etc were not listed on the class reference
page, but they were counted and a link to the base
class was provided for them, eg:

2 public functions inherited from QAbstractListModel
39 public functions inherited from QAbstractItemModel
31 public functions inherited from QObject

Somehow, this got broken, so that all these inherited
things were listed on the class reference page as if
they were members of the class. But they liunked to
the documentation in the base class.

This now works correctly again. It simnplifies the
class reference pages a lot.

Task-number: QTBUG-27496
Change-Id: If493da8cbf81634f1344b12094d9a06f8528e8e5
Reviewed-by: Jerome Pasion <jerome.pasion@digia.com>
Reviewed-by: Lars Knoll <lars.knoll@digia.com>