Columns missing from Google Code version.

[dotkrnl]

In table problems, columns sample_Program, ratio, error, difficulty, submit_user and case_time_limit were missing from Google Code version.

In my opinion, redundancy sample_Program, ratio, error and submit_user should be removed. And difficulty and case_time_limit should be implemented and documented, or removed.

表 problems 中，列 sample_Program, ratio, error, difficulty, submit_user 和 case_time_limit 并不在 Google Code 版本中。

我认为，sample_Program, ratio, error 与 submit_user 为冗余数据，需要被移除。而 difficulty 和 case_time_limit 的功能需要被实现并文档，或是决定移除。

[freefcw]

历史遗留，先移除这些字段了

[freefcw]

fixed, via 31cebdc44ae1faaefa729e0569d10a99e47c09ea