Comment 1 for bug 396322

Fix commited in rev21749:

 - Fix bug #396322: "Spell checker crashes the OS X package"
     - Include the aspell dictionary files in the app bundle.
     - Show an error if at least the en dictionary files are not available.
     - Replace the GtkOptionMenu (for selecting which dictionary to add
        extra words to) with a GtkComboBox since this one behaves correctly
        when it is insensitive. GtkOptionMenu is deprecated and the menu
        would appear when clicking on the insensitive widget and then could
        not be closed.