Associated Press: The Coast Guard has demanded that BP step up its efforts to contain the oil gushing into the Gulf of Mexico by the end of the weekend, telling the British oil giant that its slow pace in stopping the spill is becoming increasingly alarming as the disaster fouled the coastline in ugly new ways Saturday. The Coast Guard sent a testy letter to BP’s chief operating officer that said the company urgently needs to pick up the pace and present a better plan to contain the spill by the time …