* Reworked how post versioning works, now more closely resembles the 1.18 strategy

app/models/post_version.rb

@@ -0,0 +1,36 @@
+class PostVersion < ActiveRecord::Base
+  belongs_to :post
+  belongs_to :updater, :class_name => "User"
+  before_validation :initialize_updater
+  
+  def self.create_from_post(post)
+    if post.created_at == post.updated_at
+      create_from_created_post(post)
+    else
+      create_from_updated_post(post)
+    end
+  end
+  
+  def initialize_updater
+    self.updater_id = CurrentUser.id
+    self.updater_ip_addr = CurrentUser.ip_addr
+  end
+  
+  def add_tag_array
+    @add_tag_array ||= add_tags.scan(/\S+/)
+  end
+  
+  def del_tag_array
+    @del_tag_array ||= del_tags.scan(/\S+/)
+  end
+  
+  def presenter
+    PostVersionPresenter.new(self)
+  end
+  
+  def reload
+    @add_tag_array = nil
+    @del_tag_array = nil
+    super
+  end
+end