Refactor for Onsite contest

1. Add read more feature in new ArticleController.
2. Expand problem data upload file size limit
3. Update fastjson and sun.mail (Two known issue occurred in CentOS)
4. Enable C++11
5. Update contest rank list page
6. Add print service
7. Update contest page
8. Update frozen board
9. Add DOMJudge result exporter (For [DOMJura](https://github.com/nickygerritsen/DOMjura), which used for showing contest result in last one hour)