9efb374ae5
Allow users to upvote a comment, then downvote it, without raising an error or having to manually remove the upvote first. The upvote is automatically removed and replaced by the downvote. Changes to the /comment_votes API: * `POST /comment_votes` and `DELETE /comment_votes` now return a comment vote instead of a comment. * The `score` param in `POST /comment_votes` is now 1 or -1, not `up` or `down.`