Softkey API should not traverse complete the widget hierarchy

Current implementation traverses the widget hierarchy all the way to the top-level window. This causes the actions from top-level window to appear on dialog windows (whose parent is the top-level window). This behavior makes it harder to use softkeys since the application needs to remove the actions from the top-level window if the dialog window does not want any actions to be visible. Softkey API should limit the traversal for the softkeys to a single window.