Shirley Mitchell, the comic actress who played Marion Strong, Lucy Ricardo's friend with the cackling laugh on the TV classic I Love Lucy, has died. She was 94. Mitchell, who was believed to be the last surviving adult castmember from the legendary CBS sitcom, died Nov. 11 of heart failure at her condominium in Westwood, her sister-in-law, the Oscar-nominated Sunset Blvd. actress Nancy Olson, told The Hollywood Reporter. Mitchell was the widow of Jay Livingston, the pop composer and lyricist who collaborated with Ray Evans on the Academy Award-winning songs “Mona Lisa” (performed by Nat King Cole), “Que Sera, Sera”...