* Continued work on improving post view templates

* Added statistics-based estimator for related tag calculator
* Fleshed out IpBan class based on changes to Danbooru 1.xx

app/models/post_vote.rb

@@ -1,5 +1,16 @@
 class PostVote < ActiveRecord::Base
   class Error < Exception ; end
   
+  attr_accessor :is_positive
+  validates_uniqueness_of :ip_addr, :scope => :post_id
+  after_save :update_post_score
   belongs_to :post
+  
+  def update_post_score
+    if is_positive
+      post.increment!(:score)
+    else
+      post.decrement!(:score)
+    end
+  end
 end