Placement of CBA in QWidgets (such as QDialog)

In Symbian^3 the CBA has been moved to be inside the CAknDialog (possibly in some other components as well). In Qt (where the CBA had actually just been improved some releases back to be Avkon-alike) it is in the control pane. Thus the UX differs between Symbian C++ and Qt applications and should thus be fixed. We should try to minimise this kind of variation in order to enable high-quality good-looking Qt applications. When using QWidget components, the UI should be as consistent as possble with Avkon applications (or in future Orbit).