Ion Auth - User groups in users table instead

[eluser]Herlevsen[/eluser]
Hi. I would like to know if anyone else has tryed moving the user group from the users_groups table into the users table. I only want a user to be able to belong to one group, so i see no need to store it in a seperate table.

So if someone has tryed, i would like to know if you had any complications, and if you can remember how much you had to change.