Review management

[astyled]

Describe the change you'd like:

User reviews page. #106

This will allow users to see what they or others have reviewed. This may require some basic privacy settings, as some users may want to post reviews but not want to let others see what sites and styles they use.

Replies, comments. #135

Let everyone respond to/comment on reviews, highlight the style author's response.

~~Edit and delete.~~ #251

Users should be able to edit and delete their reviews. If responds/comments will be implemented for reviews, deleting a review with comments should keep the review and the comments but remove the review author and content.

Review history

This would be useful to have a history for a user's review of the style. Not as fancy as on GitHub, but at least to know when the review was posted, edited, deleted, and posted again.