Revert "FEATURE: Use configured quotation marks in fancy topic title"

This reverts most of commit ce8e099639.

The rake task to update fancy topic titles is still there, because that's useful even without this feature.

app/models/site_setting.rb

@@ -3,7 +3,6 @@
 require 'site_setting_extension'
 require_dependency 'global_path'
 require_dependency 'site_settings/yaml_loader'
-require 'htmlentities'
 
 class SiteSetting < ActiveRecord::Base
   extend GlobalPath
@@ -123,7 +122,6 @@ class SiteSetting < ActiveRecord::Base
     @attachment_content_type_blacklist_regex = nil
     @attachment_filename_blacklist_regex = nil
     @unicode_username_whitelist_regex = nil
-    @pretty_quote_entities = nil
   end
 
   def self.attachment_content_type_blacklist_regex
@@ -139,22 +137,6 @@ class SiteSetting < ActiveRecord::Base
       ? Regexp.new(SiteSetting.unicode_username_character_whitelist) : nil
   end
 
-  def self.pretty_quote_entities
-    @pretty_quote_entities ||= begin
-      htmlentities = HTMLEntities.new
-      quotation_marks = SiteSetting.markdown_typographer_quotation_marks
-        .split("|")
-        .map { |quote| htmlentities.encode(quote, :basic, :named, :decimal) }
-
-      {
-        double_left_quote: quotation_marks[0],
-        double_right_quote: quotation_marks[1],
-        single_left_quote: quotation_marks[2],
-        single_right_quote: quotation_marks[3]
-      }
-    end
-  end
-
   # helpers for getting s3 settings that fallback to global
   class Upload
     def self.s3_cdn_url