Noticed this while reviewing #13529, but it's also in master @ 5ba77df. On macOS 10.13.6:

<img width="209" alt="schermafbeelding 2018-08-01 om 16 22 09" src="https://user-images.githubusercontent.com/10217/43527498-0f571db4-95a7-11e8-8d90-7863947a7689.png">


<img width="178" alt="schermafbeelding 2018-08-01 om 16 12 51" src="https://user-images.githubusercontent.com/10217/43526994-c9a515ec-95a5-11e8-96b8-9e2513e9aac5.png">

* `Show` in the action menu doesn't work if the app was hidden by `Command + H`, it does work when hidden through this menu
* send and receive don't unhide the window when opened for the action menu. It does navigate to the right tab. The other actions do work (sign, verify & debug window)

Clicking "Toon" (= macOS native show) does work, suggesting the GUI uses some non-native method of hiding.
{
        timeBehindText = QObject::tr("%n hour(s)","",secs/HOUR_IN_SECONDS);
    }
    else if(secs < 2*WEEK_IN_SECONDS)
    {
        timeBehindText = QObject::tr("%n day(s)","",secs/DAY_IN_SECONDS);
    }
    else if(secs < YEAR_IN_SECONDS)
    {
        timeBehindText = QObject::tr("%n week(s)","",secs/WEEK_IN_SECONDS);
    }
    else
    {
        qint64 years = secs / YEAR_IN_SECONDS;
        qint64 remainder = secs % YEAR_IN_SECONDS;
        timeBehindText = QObject::tr("%1 and %2").arg(QObject::tr("%n year(s)", "", years)).arg(QObject::tr("%n week(s)","", remainder/WEEK_IN_SECONDS));
    }
    return timeBehindText;
}
QString formatBytes(uint64_t bytes)
{
    if(bytes < 1024)
        return QString(QObject::tr("%1 B")).arg(bytes);
    if(bytes < 1024 * 1024)
        return QString(QObject::tr("%1 KB")).arg(bytes / 1024);
    if(bytes < 1024 * 1024 * 1024)
        return QString(QObject::tr("%1 MB")).arg(bytes / 1024 / 1024);
    return QString(QObject::tr("%1 GB")).arg(bytes / 1024 / 1024 / 1024);
}
qreal calculateIdealFontSize(int width, const QString& text, QFont font, qreal minPointSize, qreal font_size) {