Fix for co-existence of QtDeclarative and QtQml

As a follow-up to commit 2f87fde9bb4bad6787101c0d135419b350b201a5, we also need
to change "hack" in the QGraphicsItem and QWidget destructor for early item
destruction to support the _qml1 variant of the QObject destroyed callback.

Task-number: QTBUG-35006

Change-Id: I65e37b1e9ddd8d14267aaba024408611b8cd3d77
Reviewed-by: Lars Knoll <lars.knoll@digia.com>
Android: Remove invalid error message

All usage of context menus prints out an error message because
onContextMenuClosed() is called more than once. We just return
silently instead if the method is called after the menu has
already been closed.

Change-Id: Ifa27ed42d188fdf670f09c4b1450b9fec0d5941f
Reviewed-by: BogDan Vatra <bogdan@kde.org>
CoreWLan: Fix potential unhandled exception assert

-[QNSListener notificationHandler:] was declared as not taking any parameter,
but used as taking a single NSNotification. This would lead to an 'unrecognized
selector' exception raised by Cocoa.

Task-number: QTBUG-26844
Change-Id: I56d03a7738c2a1b9dcf3cdecc696b01e65d7b233
Reviewed-by: Liang Qi <liang.qi@digia.com>