A new school year begins at Homewood-Flossmoor High School with a familiar greeter. Andrew Lindstrom, aka "Mr. Red and White," stood outside the south building starting at 6:45 a.m. Wednesday to welcome teachers and students to the first day of the fall semester. "Good morning. Welcome!" he said to each group of students walking past. "Are you ready?" Students responded variously with "Yes!" or "Not really" but most of them returned Lindstrom's smile. "I always get a smile," he said. "It's a great feeling. It's encouraging.It starts their day off right." He . . .