Meneley Elementary School Principal Becky Rugger frequently refers to her staff members, students and parents as "rock stars.""Because we're so talented. My teachers, they have so many talents," Rugger said Wednesday in her office. "We're making student achievement a goal, kind of like rock stars who want that platinum record or whatever. We work hard."There's also the appeal of alliteration." 'Rock star' starts with an 'R,'" Rugger said. "Just like Mrs. Rugger's three 'R's - respect, responsibility and resilience."But the analogy of pop stardom may be understating it. How many rock stars could set the conditions for double-digit gains in …