Bug 591763 - Add application window menu

Bug 591763 - Add application window menu

When we have multiple windows for an application, implement the following
behavior:

* On click + immediate release, go to the most recently used
* On click, hold for 0.6s, pop up a menu with windows, filtering
  the window list to just those windows.
  Mouse over on the window list highlights the moused-over window.

Implement this by splitting well item into InactiveWellItem
and RunningWellItem, sharing a base class BaseWellItem.