Comment 10 for bug 1561457

OK, this is the documentation I found:

https://doc.qt.io/archives/qq/qq19-plurals.html

http://doc.qt.io/qt-5/i18n-source-translation.html

Their usage example is:

    int n = messages.count();
    showMessage(tr("%n message(s) saved", "", n));

The QT version on my Ubuntu is too old to work on this, and it won't update easily. So, I can only start working on this once Ubuntu 16.04 is out, when an update will make sense.