Create Update By
=========
Provides optional functionality on "save" and "update_attributes" methods
that allows developers to pass the user id as a parameter.

Example:

Assume you have a books table

	create_table :books do |t|
	  t.column :created_at, :datetime
	  t.column :updated_at, :datetime
	  t.column :title, :string
	  t.column :created_by, :integer
	  t.column :updated_by, :integer
	end
	
   In your controller, you can now do

   b = Book.new
   b.title = "My Book'
   b.save(session[:user_id]
   
   
   If you don't have created_by or updated_by in your table, the stamping will not occur.
   No additonal configuration is needed.
   

Acknowledgements:
Thanks to DeLynn Berry, the creator of the original Userstamp plugin for the idea.
The Userstamp plugin can be found at 
http://www.delynnberry.com/pages/userstamp/

This plugin was created because I wanted to provide more control 
over the assignment of created_by and updated_by.