[Refactoring] DB UPDATE

[DONE]
- database severely updated
- .gitignore : now ignores [uploads/*] & [bugreport/*]
- change convention of all codes including application.const to under_score
- overall changes in application/controllers, models, static/js, static/css, lib
- major bugfix

[TODO]
- apply static-analyzer
- bugcheck : code-submit, league-system