Reviewed by Robert P. Moyer Bob Moyer reviews the final book by one of the best mystery novelists of the late 20th century. ANOTHER DAY’S PAIN. By K.C. Constantine. Mysterious Press. 232 pages. $26.95 With the posthumous publication of his 18th Rocksburg novel, K.C. Constantine deserves more than a review, he deserves an homage. He was…