show rotating spinner when block download out of date, tick otherwise

src/qt/bitcoingui.h

@@ -57,6 +57,7 @@ private:
     QLabel *labelConnections;
     QLabel *labelConnectionsIcon;
     QLabel *labelBlocks;
+    QLabel *labelBlocksIcon;
     QLabel *progressBarLabel;
     QProgressBar *progressBar;
 
@@ -74,6 +75,8 @@ private:
     QSystemTrayIcon *trayIcon;
     TransactionView *transactionView;
 
+    QMovie *syncIconMovie;
+
     void createActions();
     QWidget *createTabs();
     void createTrayIcon();