G-Man by Stephen Hunter Blue Rider Press/ Penguin Random House, $27.00, 443 pages, ISBN 978-0-399-57460-3 The Great Depression of the 1930s was a time of unrelenting misery, hardship and economic deprivation. It was an era that left indelible scars upon all who lived through it, for who could forget the massive unemployment, the endless bread lines, or the dislocation and migration of tens of thousands of impoverished farmers who’d