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/walletmodel.h

@@ -165,7 +165,7 @@ public slots:
     /* New transaction, or transaction changed status */
     void updateTransaction(const QString &hash, int status);
     /* New, updated or removed address book entry */
-    void updateAddressBook(const QString &address, const QString &label, bool isMine, int status);
+    void updateAddressBook(const QString &address, const QString &label, bool isMine, const QString &purpose, int status);
     /* Current, immature or unconfirmed balance might have changed - emit 'balanceChanged' if so */
     void pollBalanceChanged();
 };