Please correct current_user_can checks

Hey,

I used your nice plugin today and had some problems. I noticed current_user_can checks has NOT (!) sign beside them, I believe, it should not have. I am talking about the line number 47,66,79 and 99 in file cleverness-to-do-list-library.class.php.

Removing them make few admin settings worked!.

https://ww.wp.xz.cn/plugins/cleverness-to-do-list/