* Add post/comment/forum vote counts to user profiles.
* Show uploaders on post votes index and allow searching by uploader.
* Show forum posters on forum votes index and allow searching by poster.
* Add unvote link to forum votes index.
* Only show unvote links to current user.
Fixes a conflict with `Enumerable#excluding` in Rails 6.
Rename Array#without and Enumerable#without to Array#excluding and
Enumerable#excluding. Old method names are retained as aliases.
