Forum Comments need improvement

[sbrunswi]

Summary
Currently we cannot comment on forum comments. There should be an ability to comment on a comment as well.

Solution
Improvements to forum post/comments

1. Allow users and admin to comment on comments
2. Track comments on stats
3. Allow users to also post in forum but post is pending approval of admin (Optional if too much work)

[sbrunswi]

@charrismatic this is still an open development issue from last fall! I think we have the comments on comments but I am not sure about 2 and 3. We also should specify the difference between general forum and cohort forum if any. We also talked about the idea that people could rate and comment on the notebooks in the result page and that those comments are visible to the submitter of the notebooks! We had discussed this in fall and since we will have this long-term hack it might be good to have more interaction... This would go into the issue on experimental features/result page ...