let's make the info of an element more free.

/**
    @brief ElementsProperties::translatedInfo
    Return the translated information key given by info
    If info don't match, return an empty string
    @param info the key to be translated
    @return
*/
QString QETApp::elementTranslatedInfoKey(const QString &info)
{
    if (info == "formula") return tr("Formule du label");
    else if (info == "label") return tr("Label");
    else if (info == "plant") return tr("Installation");
    else if (info == "location") return tr("Localisation");
 
    else if (info == "comment") return tr("Commentaire");
    else if (info == "function") return tr("Fonction");
    else if (info == "auxiliary1") return tr("Bloc auxiliaire 1");
    else if (info == "auxiliary2") return tr("Bloc auxiliaire 2");
 
    else if (info == "description") return tr("Description textuelle");
    else if (info == "designation") return tr("Numéro d'article");
    else if (info == "manufacturer") return tr("Fabricant");
    else if (info == "manufacturer_reference") return tr("Numéro de commande");
    else if (info == "machine_manufacturer_reference") return tr("Numéro interne");
    else if (info == "supplier") return tr("Fournisseur");
    else if (info == "quantity") return tr("Quantité");
    else if (info == "unity") return tr("Unité");
 
    else return QString();
}