In a candid interview with the Observer newspaper Sunday, Scottish comedian Billy Connolly, famed for his flowing locks and impudent humor, has revealed he suffered years of sexual abuse as a child at the hands of his father.   The abuse was a dark secret through most of his life, only revealing it to his wife after his father William died in 1989.   He and his sister were raised by his father and two aunts in poverty in Glasgow after his mother left the family when he was three.  He told the paper he slept on a sofa every night with his father, who would frequently come home drunk.  I remember (the abuse) happening a lot.  I would pray for the holidays.  I wouldn't wait for us to go to the seaside because then we had separate beds, he said.