New API stuff to check

[Choumiko]

LuaTrain::get_rails() LuaTrain::go_to_station() LuaTrain::path LuaTrain::max_forward_speed and max_backward_speed on_train_schedule_changed event LuaEntity::get_train_stop_trains() LuaGameScript::get_train_stops(), LuaSurface::get_train_stops(), and LuaForce::get_train_stops() LuaGameScript::tick_paused and ticks_to_run read/write (debugging?)