Bug 182190 [StatusHandling] [Wizards] getControl assert on wizard page has no message
M6 If you forget to set the control on your wizard page our assert gives no feedback. We need an error message.
bundles/org.eclipse.jface/src/org/eclipse/jface/wizard/WizardDialog.java
title = ""; 
		}
        getShell().setText(title);
    }
	/* (non-Javadoc)
	 * @see org.eclipse.jface.dialogs.IPageChangeProvider#getSelectedPage()
	 */
	public Object getSelectedPage() {
		return getCurrentPage();
	}
   /* (non-Javadoc)
    * @see org.eclipse.jface.dialog.IPageChangeProvider#addPageChangedListener()
    */
	public void addPageChangedListener(IPageChangedListener listener) {
		pageChangedListeners.add(listener);
	}
   /* (non-Javadoc)
    * @see org.eclipse.jface.dialog.IPageChangeProvider#removePageChangedListener()
    */
	public void removePageChangedListener(IPageChangedListener listener) {
		pageChangedListeners.remove(listener);		
	}
 
	/**
     * Notifies any selection changed listeners that the selected page
     * has changed.
     * Only listeners registered at the time this method is called are notified.
     *
     * @param event a selection changed event
     *