Add network traffic graph

src/qt/clientmodel.h

@@ -35,6 +35,9 @@ public:
     int getNumBlocks() const;
     int getNumBlocksAtStartup();
 
+    quint64 getTotalBytesRecv() const;
+    quint64 getTotalBytesSent() const;
+
     double getVerificationProgress() const;
     QDateTime getLastBlockDate() const;
 
@@ -74,6 +77,7 @@ signals:
     void numConnectionsChanged(int count);
     void numBlocksChanged(int count, int countOfPeers);
     void alertsChanged(const QString &warnings);
+    void bytesChanged(quint64 totalBytesIn, quint64 totalBytesOut);
 
     //! Asynchronous message notification
     void message(const QString &title, const QString &message, unsigned int style);