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.
{
    connect(tableView->horizontalHeader(), &QHeaderView::sectionResized, this, &TableViewLastColumnResizingFixer::on_sectionResized);
    connect(tableView->horizontalHeader(), &QHeaderView::geometriesChanged, this, &TableViewLastColumnResizingFixer::on_geometriesChanged);
}
void TableViewLastColumnResizingFixer::disconnectViewHeadersSignals()
{
    disconnect(tableView->horizontalHeader(), &QHeaderView::sectionResized, this, &TableViewLastColumnResizingFixer::on_sectionResized);
    disconnect(tableView->horizontalHeader(), &QHeaderView::geometriesChanged, this, &TableViewLastColumnResizingFixer::on_geometriesChanged);
}
void TableViewLastColumnResizingFixer::setViewHeaderResizeMode(int logicalIndex, QHeaderView::ResizeMode resizeMode)
{
    tableView->horizontalHeader()->setSectionResizeMode(logicalIndex, resizeMode);
}
void TableViewLastColumnResizingFixer::resizeColumn(int nColumnIndex, int width)
{
    tableView->setColumnWidth(nColumnIndex, width);
    tableView->horizontalHeader()->resizeSection(nColumnIndex, width);
}
int TableViewLastColumnResizingFixer::getColumnsWidth()
{
    int nColumnsWidthSum = 0;
    for (int i = 0; i < columnCount; i++)
    {
        nColumnsWidthSum += tableView->horizontalHeader()->sectionSize(i);
    }
    return nColumnsWidthSum;
}
int TableViewLastColumnResizingFixer::getAvailableWidthForColumn(int column)