OVERLAND PARK, Kansas (Reuters) - Coming soon to a movie screen near you: prayers, politics and a feature-length film, united in an effort to mobilize religious groups around global warming concerns in time for the U.S. midterm election. With a new documentary titled "The Great Warming" as their chief campaign tool, a coalition of religious leaders, environmentalists and businesses are spreading copies of the film into churches around the country. Voter guides and themed sermons are also part of the plan. The aim of the screenings, like one held in Kansas last week, is to turn the large and powerful...