MainWindow: make_actions_menu is added.
Small fixes.
make_remote_menu: refactoring.
_make_menu is added.
Refactoring.
make_states_menu: refactoring.
update_states_menu: use _make_action.
Replace super -> self.
create_main_menu is added.
create_commites_dock is added.
MainWindow: add more methods.
MainWindow: create_docks is added.