NEW YORK (Reuters) - Former U.S. President Bill Clinton is "The Most Influential Man in the World," according to Esquire magazine. The magazine has designated him as "the most powerful agent of change in the world" despite his lack of electoral standing and the fact he was laid low by a heart attack ahead of last year's presidential election. The magazine highlights Clinton's accomplishments in its December issue, which goes on newsstands on Thursday, profiling the world's "Best and Brightest" men and women. Since leaving office, Clinton has been so active that his post-presidency amounts to "a third term" for...