In 11.10, the Unity alt-tab switcher brought all the windows belonging to an application to the front when switching to the application like on Mac (unless you waited for long enough that the app's switcher entry expanded to a window selection in which case you got to select which window to switch to).
In 12.04, switching to an app with multiple window open (in the same workspace) brings to the from one of the windows. (I see no logic in which one is brought to the front.)
How do I, under 12.04, revert to the alt-tab behavior of 11.10 so that switching to an app brings to the front all the windows of that app?