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.
bool setCurrentWallet(const QString& name);
    bool setCurrentWalletBySelectorIndex(int index);
    /** Set the UI status indicators based on the currently selected wallet.
    */
    void updateWalletStatus();
private:
    /** Set the encryption status as shown in the UI.
       @param[in] status            current encryption status
       @see WalletModel::EncryptionStatus
    */
    void setEncryptionStatus(int status);
    /** Set the hd-enabled status as shown in the UI.
     @param[in] hdEnabled         current hd enabled status
     @see WalletModel::EncryptionStatus
     */
    void setHDStatus(int hdEnabled);
public Q_SLOTS:
    bool handlePaymentRequest(const SendCoinsRecipient& recipient);
    
    void incomingTransaction(const QString& date, int unit, const CAmount& amount, const QString& type, const QString& address, const QString& label, const QString& walletName);
#endif 
private:
    
    void updateProxyIcon();
public Q_SLOTS:
#ifdef ENABLE_WALLET
    
    void gotoOverviewPage();
    
    void gotoHistoryPage();