Adding frequent_unsuccessful_level_sources table, and the rake task that updates it.
Adding a infrequent task list for seed.rake.
Added add_pop_hint page and add_pop_hint_per_level page with the flow.
Better UI for the add hint page, showing number of students having issue with the problem, as well as character counts.
Only show programs that do not have hint.
Merge branch 'master' into feedback_collect
Only admin can access this page.
Updated based on Chris's comment.
Updated based on comments.
Bug fix.
Merge pull request #263 from nanan9177/feedback_collect

Feedback collect