Remember Me Security

We can base the revisit on a random number cookie stored in the database and linked to a user account.  It can be paired with a the user agent, but not the IP address as I want to be able to accomodate my iphone moving between cell towers and hot spots.

On Login

1. Check to see if the cookie exists
2. If cookie and User agent match an entry in the login table where logout is null and there are no later entries
   1. Set Session variables
   2. Create new entry in login table with new random number and assign that number to a cookie
      
3. If the cookie doesn't exist or doesn't match
   1. Prompt for login
   2. Create new entry in login table with new random number and assign that number to a cookie