DISCUSSION OF WALT, ELSPETH ROSTOW JOINING UT FACULTY; LBJ DISCUSSES WALT ROSTOW'S WH DUTIES, REFUTES CRITICISM OF HIS ROLE IN VIETNAM POLICY, PRAISES ELSPETH ROSTOW; RANSOM CONGRATULATES LBJ ON BIRTH OF LUCINDA ROBB; UT INFLUENCE ON LYNDA ROBB, LADY BIRD