Timetable: Implement autofill/automate for taken conditional orders.

Fix wrong timetable values being set after using skip or send to depot.
Add timetabled flag for conditional order branch taken travel time.

src/order_backup.cpp

@@ -89,6 +89,7 @@ void OrderBackup::DoRestore(Vehicle *v)
 	/* Make sure orders are in range */
 	v->UpdateRealOrderIndex();
 	if (v->cur_implicit_order_index >= v->GetNumOrders()) v->cur_implicit_order_index = v->cur_real_order_index;
+	if (v->cur_timetable_order_index >= v->GetNumOrders()) v->cur_timetable_order_index = INVALID_VEH_ORDER_ID;
 
 	/* Restore vehicle group */
 	DoCommand(0, this->group, v->index, DC_EXEC, CMD_ADD_VEHICLE_GROUP);