Eliminate various dead code.

app/jobs/delete_upload_files_job.rb

@@ -1,8 +0,0 @@
-class DeleteUploadFilesJob < ApplicationJob
-  queue_as :default
-  queue_with_priority 20
-
-  def perform(md5, file_ext, upload_id)
-    # do nothing
-  end
-end

app/presenters/post_presenter.rb

@@ -1,4 +1,4 @@
-class PostPresenter < Presenter
+class PostPresenter
   attr_reader :pool, :next_post_in_pool
   delegate :tag_list_html, :split_tag_list_html, :split_tag_list_text, :inline_tag_list_html, to: :tag_set_presenter
 
@@ -150,10 +150,6 @@ class PostPresenter < Presenter
     @tag_set_presenter ||= TagSetPresenter.new(@post.tag_array)
   end
 
-  def preview_html
-    PostPresenter.preview(@post)
-  end
-
   def humanized_essential_tag_string
     @humanized_essential_tag_string ||= tag_set_presenter.humanized_essential_tag_string(default: "##{@post.id}")
   end

app/presenters/presenter.rb

@@ -1,17 +0,0 @@
-class Presenter
-  def self.h(s)
-    CGI.escapeHTML(s.to_s)
-  end
-
-  def self.u(s)
-    CGI.escape(s)
-  end
-
-  def h(s)
-    CGI.escapeHTML(s)
-  end
-
-  def u(s)
-    CGI.escape(s)
-  end
-end

app/presenters/tag_set_presenter.rb

@@ -3,7 +3,7 @@
 #   This class makes it easy to fetch the categories for all the
 #   tags in one call instead of fetching them sequentially.
 
-class TagSetPresenter < Presenter
+class TagSetPresenter
   extend Memoist
   attr_reader :tag_names
 
@@ -147,5 +147,13 @@ class TagSetPresenter < Presenter
     html
   end
 
+  def h(s)
+    CGI.escapeHTML(s)
+  end
+
+  def u(s)
+    CGI.escape(s)
+  end
+
   memoize :tags, :tags_by_category, :ordered_tags, :humanized_essential_tag_string
 end

app/presenters/upload_presenter.rb

@@ -1,4 +1,4 @@
-class UploadPresenter < Presenter
+class UploadPresenter
   attr_reader :upload
   delegate :inline_tag_list_html, to: :tag_set_presenter