GUI: Fix handling UTF-8 strings in sources.

Our source files are UTF-8 and as such contain some chars outside 7-bit ASCII. To handle UTF-8 correctly we must set text codec for QT to UTF-8.

gui/main.cpp

@@ -18,6 +18,7 @@
 
 
 #include <QApplication>
+#include <QTextCodec>
 #include "mainwindow.h"
 
 int main(int argc, char *argv[])
@@ -25,6 +26,10 @@ int main(int argc, char *argv[])
     QApplication app(argc, argv);
     app.setWindowIcon(QIcon(":icon.png"));
 
+    // Set codecs so that UTF-8 strings in sources are handled correctly.
+    QTextCodec::setCodecForTr(QTextCodec::codecForName("UTF-8"));
+    QTextCodec::setCodecForCStrings(QTextCodec::codecForName("UTF-8"));
+
     MainWindow window;
     window.show();
     return app.exec();