Guardian: BP says oil has stopped leaking into the Gulf of Mexico from the Deepwater Horizon rig for the first time since April. The oil well has been sealed with a cap, which engineers are now monitoring to see if it holds. They will watch pressure readings to see if the cap is working. High pressure is better, because it means the oil is staying within the cap and not escaping through an unknown leak. Low pressure means there could be another leak. BP executive Kent Wells said …