Now that future movie mogul Lou Madigan is five months from breaking ground for his 15-acre film studio at the Brooklyn Navy Yard, he's spilling all the beans. And, boy, did the crowd eat it up. In a talk that could have been titled "How to Become a Brooklyn Movie Studio CEO Without Getting Your Legs Broken," Madigan told a laughing, clapping crowd of 130 people yesterday about the four-year ordeal he and his partner, Cary Dean Hart, went through trying to secure financing to