Stephen Olford, known worldwide as the “prince of preachers” and the “pastor’s pastor,” died of a stroke Aug. 29. He was 86.     Founder and chairman of the board of Memphis, Tenn.-based Olford Ministries International (OMI), Olford left a world of influence among Christian church leaders wherever he went, including Alabama.     Roger Willmore, pastor of First Baptist Church, Boaz,…