qt: Handle address purpose in incremental updates

Correctly use the purpose of addresses that are added after the start
of the client. Addresses with purpose "refund" and "change" should not
be visible in the GUI. This is now handled correctly.

src/qt/addresstablemodel.h

@@ -85,7 +85,7 @@ signals:
 public slots:
     /* Update address list from core.
      */
-    void updateEntry(const QString &address, const QString &label, bool isMine, int status);
+    void updateEntry(const QString &address, const QString &label, bool isMine, const QString &purpose, int status);
 
     friend class AddressTablePriv;
 };