remove unused and unneccesary user_id from taggings table.

this way we can stay closer to the defaults of has_many_polymorphs thus making upgrading easier

app/models/user.rb

@@ -104,8 +104,6 @@ class User < ActiveRecord::Base
            end
   has_many :notes, :order => "created_at DESC", :dependent => :delete_all
   has_one :preference, :dependent => :destroy
-  has_many :taggings
-  has_many :tags, :through => :taggings, :select => "DISTINCT tags.*"
   
   attr_protected :is_admin