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.
{
    
    if (!walletModel || !clientModel || clientModel->node().isInitialBlockDownload())
        return;
    TransactionTableModel *ttm = walletModel->getTransactionTableModel();
    if (!ttm || ttm->processingQueuedTransactions())
        return;
    QString date = ttm->index(start, TransactionTableModel::Date, parent).data().toString();
    qint64 amount = ttm->index(start, TransactionTableModel::Amount, parent).data(Qt::EditRole).toULongLong();
    QString type = ttm->index(start, TransactionTableModel::Type, parent).data().toString();
    QModelIndex index = ttm->index(start, 0, parent);
    QString address = ttm->data(index, TransactionTableModel::AddressRole).toString();
    QString label = ttm->data(index, TransactionTableModel::LabelRole).toString();
    Q_EMIT incomingTransaction(date, walletModel->getOptionsModel()->getDisplayUnit(), amount, type, address, label, walletModel->getWalletName());
}
void WalletView::gotoOverviewPage()