QRcode를 생성하는 라이브러리
http://phpqrcode.sourceforge.net/
http://sourceforge.net/projects/phpqrcode/files/
https://github.com/edent/QR-Generator-PHP/
graph.google.com 사용하는 라이브러리
http://www.shayanderson.com/php/php-qr-code-generator-class.htm
http://www.shayanderson.com/php/php-barcode-generator-class-code-39.htm
