ALLEN THANKS LBJ FOR HIS STATEMENT UPON DEATH OF MLK, REPORTS ON SITUATION IN ATLANTA; LBJ'S CALL TO CORETTA SCOTT KING; RIOTING IN WASHINGTON, DC; POSTPONEMENT OF LBJ'S TRIP TO HONOLULU; LBJ'S 3/31/68 SPEECH; LADY BIRD JOHNSON THANKS ALLEN FOR HIS WORK