qt: use SendCoinsRecipient for payment request information

This brings some symmetry into the design by using the same object
both for incoming URIs that are parsed as for outgoing URIs that
are formatted.

src/qt/receiverequestdialog.h

@@ -1,6 +1,8 @@
 #ifndef QRCODEDIALOG_H
 #define QRCODEDIALOG_H
 
+#include "walletmodel.h"
+
 #include <QDialog>
 #include <QImage>
 #include <QLabel>
@@ -34,7 +36,7 @@ class ReceiveRequestDialog : public QDialog
     Q_OBJECT
 
 public:
-    explicit ReceiveRequestDialog(const QString &addr, const QString &label, quint64 amount, const QString &message, QWidget *parent = 0);
+    explicit ReceiveRequestDialog(const SendCoinsRecipient &info, QWidget *parent = 0);
     ~ReceiveRequestDialog();
 
     void setModel(OptionsModel *model);
@@ -49,7 +51,7 @@ private slots:
 private:
     Ui::ReceiveRequestDialog *ui;
     OptionsModel *model;
-    QString address;
+    SendCoinsRecipient info;
 
     void genCode();
     QString getURI();