This lib is fork from google code: https://code.google.com/p/kaptcha/
The original project is so simple that can't match the requirement, and I just fork it and add some personalized customization.
###1. Add the Chinese charcter in the captcha The charcter default setting is all of the Chinese charcter.
###2. Improve the Text Creator algorithms We don't wanna to have same Chinese charcter in one captcha(it't not matter about English charcter).