FIX: 1380091 Use locale time

Fixes Bug 1380091

Now we display the time with a format appropriate to the chosen locale
What about that 
```
if (userLocale.isEmpty()) {
    m_sTimeFormat = QLocale::system().timeFormat(format);
} else {
    QScopedPointer<QLocale> p(new QLocale(userLocale));
    m_sTimeFormat = p->timeFormat(format);
}
```
- no reference counting 
-  no unnecessary new delete cycle for the default case