The belongs_to_creator macro was used to initialize the creator_id field
to the CurrentUser. This made tests complicated because it meant you had
to create and set the current user every time you wanted to create an
object, when lead to the current user being set over and over again. It
also meant you had to constantly be aware of what the CurrentUser was in
many different contexts, which was often confusing. Setting creators
explicitly simplifies everything greatly.
* 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.
