void add_single_channel_controller_item (Gtk::Menu_Helpers::MenuList& ctl_items, int ctl, const std::string& name);
void add_multi_channel_controller_item (Gtk::Menu_Helpers::MenuList& ctl_items, int ctl, const std::string& name);
void add_single_channel_controller_item (Gtk::Menu_Helpers::MenuList& ctl_items, int ctl, const std::string& name);
void add_multi_channel_controller_item (Gtk::Menu_Helpers::MenuList& ctl_items, int ctl, const std::string& name);