'Defines what happens when you press \'preferences\' on the menu.
Sends as a callback reloadWsManager, so if the user actually
changes her Couch URL, the sidebar will reload reflecting the
new workspaces available'

def on_preferences(self, action=None, param=None):

    preference_window = PreferenceWindowDialog(self.reload_workspaces, self.connect_to_couch, self.window)
    preference_window.show_all()
