Function step_detach_widget

UnitTests/UnitTest_AttachDetach/DemoKeeper.cpp:118–125

	}

	static void step_detach_widget()
	{
		MyGUI::Widget* widget = get_random(all_widgets);
		if (!widget)
			return;
		widget->detachFromWidget(get_layer());
		test_widgets();
	}

	static void step_detach_widget(int _count)
	{