Print: add UI for a print dialog

PrintOptions is a QWidget class to be used as an
addition to a future print dialog (possibly based on
QPrintDialog). Currently only contains a couple of
radio buttons.

PrintDialog (printdialog.cpp/h) which is a basic QDialog
is currently added for testing only and it holds
an instance of PrintOptions.

Calling File->Print opens this test dialog for now.

Signed-off-by: Lubomir I. Ivanov <neolit123@gmail.com>

qt-ui/printdialog.h

@@ -0,0 +1,25 @@
+#ifndef PRINTDIALOG_H
+#define PRINTDIALOG_H
+
+#include <QDialog>
+#include "../display.h"
+#include "printoptions.h"
+
+// should be based on a custom QPrintDialog class
+class PrintDialog : public QDialog {
+Q_OBJECT
+
+public:
+	static PrintDialog *instance();
+	void runDialog();
+	struct options printOptions;
+
+private:
+	explicit PrintDialog(QWidget *parent = 0, Qt::WindowFlags f = 0);
+	PrintOptions *optionsWidget;
+
+private slots:
+	void printClicked();
+};
+
+#endif