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.
QPushButton *exportButton = new QPushButton(tr("&Export"), this);
    exportButton->setToolTip(tr("Export the data in the current tab to a file"));
    if (platformStyle->getImagesOnButtons()) {
        exportButton->setIcon(platformStyle->SingleColorIcon(":/icons/export"));
    }
    hbox_buttons->addStretch();
    hbox_buttons->addWidget(exportButton);
    vbox->addLayout(hbox_buttons);
    transactionsPage->setLayout(vbox);
    receiveCoinsPage = new ReceiveCoinsDialog(platformStyle);
    sendCoinsPage = new SendCoinsDialog(platformStyle);
    usedSendingAddressesPage = new AddressBookPage(platformStyle, AddressBookPage::ForEditing, AddressBookPage::SendingTab, this);
    usedReceivingAddressesPage = new AddressBookPage(platformStyle, AddressBookPage::ForEditing, AddressBookPage::ReceivingTab, this);
    addWidget(overviewPage);
    addWidget(transactionsPage);
    addWidget(receiveCoinsPage);
    addWidget(sendCoinsPage);
    
    connect(overviewPage, &OverviewPage::transactionClicked, transactionView, static_cast<void (TransactionView::*)(const QModelIndex&)>(&TransactionView::focusTransaction));
    connect(overviewPage, &OverviewPage::outOfSyncWarningClicked, this, &WalletView::requestedSyncWarningInfo);
    
    connect(sendCoinsPage, &SendCoinsDialog::coinsSent, transactionView, static_cast<void (TransactionView::*)(const uint256&)>(&TransactionView::focusTransaction));
    
    connect(exportButton, &QPushButton::clicked, transactionView, &TransactionView::exportClicked);
    
    connect(sendCoinsPage, &SendCoinsDialog::message, this, &WalletView::message);
    
    connect(transactionView, &TransactionView::message, this, &WalletView::message);
}
WalletView::~WalletView()