added post mod details

app/models/post_moderation_detail.rb

@@ -0,0 +1,19 @@
+class PostModerationDetail < ActiveRecord::Base
+  belongs_to :post
+  belongs_to :user
+  
+  def self.filter(posts, user, select_hidden = false)
+    hidden = where(:user_id => user.id).select("post_id").map(&:post_id)
+    if select_hidden
+      posts.select {|x| hidden.include?(x.id)}
+    else
+      posts.reject {|x| hidden.include?(x.id)}
+    end
+  end
+  
+  def self.prune!
+    joins(:post).where("posts.is_pending = FALSE AND posts.is_flagged = FALSE").each do |hidden_post|
+      hidden_post.destroy
+    end
+  end
+end