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.

js/ui/overview.js

@@ -232,7 +232,7 @@ Overview.prototype = {
     // This allows the user to place the item on any workspace.
     handleDragOver : function(source, actor, x, y, time) {
         if (source instanceof GenericDisplay.GenericDisplayItem
-            || source instanceof AppDisplay.WellDisplayItem) {
+            || source instanceof AppDisplay.BaseWellItem) {
             if (this._activeDisplayPane != null)
                 this._activeDisplayPane.close();
             return true;
@@ -390,6 +390,29 @@ Overview.prototype = {
          this.hide();
     },
 
+    /**
+     * setHighlightWindow:
+     * @metaWindow: A #MetaWindow
+     *
+     * Draw the user's attention to the given window @metaWindow.
+     */
+    setHighlightWindow: function (metaWindow) {
+        if (this._workspaces)
+            this._workspaces.setHighlightWindow(metaWindow);
+    },
+
+    /**
+     * setWindowApplicationFilter:
+     * @id: A string application identifier
+     *
+     * Hide all windows which are not owned by the application
+     * identified by @id.
+     */
+    setWindowApplicationFilter: function (id) {
+        if (this._workspaces)
+            this._workspaces.setWindowApplicationFilter(id);
+    },
+
     //// Private methods ////
 
     _showDone: function() {