Migration from v0.5 to v0.6

Renamed methods

• FactoryComponent::output_to_parent_input() => FactoryComponent::forward_to_parent()

Actions

• RelmActionGroup::add_action() now consumes the action
• Use RelmActionGroup::register_for_widget() and RelmActionGroup::register_for_main_application() instead of WidgetExt::insert_action_group()