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 isDust(interfaces::Node& node, const QString& address, const CAmount& amount);
    
    QString HtmlEscape(const QString& str, bool fMultiLine=false);
    QString HtmlEscape(const std::string& str, bool fMultiLine=false);
    /** Copy a field of the currently selected entry of a view to the clipboard. Does nothing if nothing
        is selected.
       @param[in] column  Data column to extract from the model
       @param[in] role    Data role to extract from the model
       @see  TransactionView::copyLabel, TransactionView::copyAmount, TransactionView::copyAddress
     */
    void copyEntryData(QAbstractItemView *view, int column, int role=Qt::EditRole);
    /** Return a field of the currently selected entry as a QString. Does nothing if nothing
        is selected.
       @param[in] column  Data column to extract from the model
       @see  TransactionView::copyLabel, TransactionView::copyAmount, TransactionView::copyAddress
     */
    QList<QModelIndex> getEntryData(QAbstractItemView *view, int column);
    void setClipboard(const QString& str);
    /** Get save filename, mimics QFileDialog::getSaveFileName, except that it appends a default suffix
        when no suffix is provided by the user.
      @param[in] parent  Parent window (or 0)
      @param[in] caption Window caption (or empty, for default)
      @param[in] dir     Starting directory (or empty, to default to documents directory)
      @param[in] filter  Filter specification such as "Comma Separated Files (*.csv)"
      @param[out] selectedSuffixOut  Pointer to return the suffix (file type) that was selected (or 0).
                  Can be useful when choosing the save file format based on suffix.
     */
    QString getSaveFileName(QWidget *parent, const QString &caption, const QString &dir,
        const QString &filter,