Select previous tab when a stream stats tab is closed

The default behaviour was to select the tab to the right of the
closed tab which is not very useful for us since the right tab
will be the Logs tab.

Fixes #331

client/portstatswindow.cpp

@@ -331,9 +331,24 @@ void PortStatsWindow::on_tbGetStreamStats_clicked()
         QDockWidget *statsDock = mainWindow->findChild<QDockWidget*>(
                                                             "statsDock");
         mainWindow->addDockWidget(Qt::BottomDockWidgetArea, dock);
+
+        // Add stream stats tab to the immediate right of port-stats ...
         mainWindow->tabifyDockWidget(statsDock, dock);
+        mainWindow->splitDockWidget(statsDock, dock, Qt::Horizontal);
+
+        // ... make it the currently visible tab  ...
         dock->show();
         dock->raise();
+
+        // ... and set tab remove behaviour
+        // XXX: unfortunately, there's no direct way to get the TabBar
+        QList<QTabBar*> tabBars = mainWindow->findChildren<QTabBar*>();
+        foreach(QTabBar* tabBar, tabBars) {
+            if (tabBar->tabText(tabBar->currentIndex())
+                            == dock->widget()->windowTitle())
+                tabBar->setSelectionBehaviorOnRemove(
+                        QTabBar::SelectPreviousTab);
+        }
     }
 
     // Get stream stats for selected ports, portgroup by portgroup