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.
{
    QUrl uriInstance(uri);
    return parseBitcoinURI(uriInstance, out);
}
QString formatBitcoinURI(const SendCoinsRecipient &info)
{
    QString ret = QString("bitcoin:%1").arg(info.address);
    int paramCount = 0;
    if (info.amount)
    {
        ret += QString("?amount=%1").arg(BitcoinUnits::format(BitcoinUnits::BTC, info.amount, false, BitcoinUnits::separatorNever));
        paramCount++;
    }
    if (!info.label.isEmpty())
    {
        QString lbl(QUrl::toPercentEncoding(info.label));
        ret += QString("%1label=%2").arg(paramCount == 0 ? "?" : "&").arg(lbl);
        paramCount++;
    }
    if (!info.message.isEmpty())
    {
        QString msg(QUrl::toPercentEncoding(info.message));
        ret += QString("%1message=%2").arg(paramCount == 0 ? "?" : "&").arg(msg);
        paramCount++;
    }
    return ret;
}
bool isDust(interfaces::Node& node, const QString& address, const CAmount& amount)