WASHINGTON - In the 50 years that Grant Goodman has known and corresponded with a colleague in the Philippines he never had any reason to suspect that their friendship was anything but spectacularly ordinary. But now he believes that the relationship has somehow sparked the interest of the Department of Homeland Security and led the agency to place him under surveillance.Last month Goodman, an 81-year-old retired University of Kansas history professor, received a letter from his friend in the Philippines that had been opened and resealed with a strip of dark green tape bearing the words “by Border Protection” and carrying the official Homeland Security seal.