The five top executives of the company that owned the Deepwater Horizon oil rig are donating their safety bonuses to the families of the workers killed in the Gulf of Mexico. More than a quarter million dollars will now be added to the fund that distributes money to the families of the eleven men who died when the offshore drilling rig blew up last year.  The announcement follows criticism of a Transocean, Ltd. filing with the SEC, claiming 2010 was its best year for safety.  The company apologized this week for some of that wording.    Transocean leased Deepwater Horizon to BP.  The explosion and subsequent leak has been called the worst oil spill in U.S. history.