NEW CALLING: The Rev. Charles R. Swindoll, senior pastor of Fullerton's First Evangelical Free Church, is also becoming the new president of Dallas Theological Seminary in Texas, his alma mater. . . . Swindoll says he wants to mold "servant-hearted leaders" who know how to communicate "truths of the Bible . . . in an accurate, clear, and practical manner." Swindoll, whose radio program "Insight for Living" is heard daily on 1,600 stations worldwide, will remain as pastor in Fullerton.