Comment files now start with a UTF-8 BOM

Added an "Apply" MessageBox button to handle the convert option asked by fossil
Converted Q_WS_* to Q_OS_* since the first no longer exists in QT5

FossilOrigin-Name: f99bd8ac7960cb1758222d2211937e99708f67f3

src/SettingsDialog.cpp

@@ -15,7 +15,7 @@
 QString SettingsDialog::SelectExe(QWidget *parent, const QString &description)
 {
 	QString filter(tr("Applications"));
-#ifdef Q_WS_WIN
+#ifdef Q_OS_WIN
 	filter += " (*.exe)";
 #else
 	filter += " (*)";