Add redaction and history limiting

History is limited to only the entries after the last redaction, unless if the user is an admin (or viewing their own post).

Any user who can edit a post is also able to redact it. This allows the owner of a post to also redact their own posts.

app/controllers/post_history_controller.rb

@@ -6,7 +6,8 @@ class PostHistoryController < ApplicationController
       return not_found
     end
 
-    @history = PostHistory.where(post_id: params[:id]).includes(:post_history_type, :user, post_history_tags: [:tag])
+    @history = PostHistory.where(post_id: params[:id]).visible(current_user)
+                          .includes(:post_history_type, :user, post_history_tags: [:tag])
                           .order(created_at: :desc).paginate(per_page: 20, page: params[:page])
     render layout: 'without_sidebar'
   end