Do cleanup work in an earlier stage to ensure correct conf saving.

src/mainwindow.cpp

@@ -337,18 +337,14 @@ MainWindow::MainWindow(QWidget *parent, const QStringList& torrentCmdLine) : QMa
 }
 
 void MainWindow::deleteBTSession() {
+  qDebug("GUI destruction");
+  hide();
   guiUpdater->stop();
   status_bar->stopTimer();
-  QBtSession::drop();
   m_pwr->setActivityState(false);
+  QBtSession::drop();
   // Save window size, columns size
   writeSettings();
-}
-
-// Destructor
-MainWindow::~MainWindow() {
-  qDebug("GUI destruction");
-  hide();
 #ifdef Q_WS_MAC
   // Workaround to avoid bug http://bugreports.qt.nokia.com/browse/QTBUG-7305
   setUnifiedTitleAndToolBarOnMac(false);
@@ -381,15 +377,12 @@ MainWindow::~MainWindow() {
   delete properties;
   delete hSplitter;
   delete vSplitter;
-  if (systrayCreator) {
+  if (systrayCreator)
     delete systrayCreator;
-  }
-  if (systrayIcon) {
+  if (systrayIcon)
     delete systrayIcon;
-  }
-  if (myTrayIconMenu) {
+  if (myTrayIconMenu)
     delete myTrayIconMenu;
-  }
   delete tabs;
   // Keyboard shortcuts
   delete switchSearchShortcut;
@@ -397,7 +390,7 @@ MainWindow::~MainWindow() {
   delete switchTransferShortcut;
   delete switchRSSShortcut;
   IconProvider::drop();
-  qDebug("Exiting GUI destructor...");
+  qDebug("Finished GUI destruction");
 }
 
 void MainWindow::defineUILockPassword() {

src/mainwindow.h

@@ -72,7 +72,6 @@ class MainWindow : public QMainWindow, private Ui::MainWindow{
 public:
   // Construct / Destruct
   MainWindow(QWidget *parent=0, const QStringList& torrentCmdLine = QStringList());
-  ~MainWindow();
   // Methods
   QWidget* getCurrentTabWidget() const;
   TransferListWidget* getTransferList() const { return transferList; }