change the dn to use uid instead of cn at account creation time

Issue Summary

hello,

thank you for the work. It will be very valuable to my site.

I ran into an issue with my install of the module. I use openldap and it is expecting a dn similar to uid=user,ou=people, etc.

When I try and create accounts via the account management interface, the debug statements showed the dn started with cn=.
I could not find where to configure this setting in the admin interface so I had to hack the code to hard code to use uid instead.

Could we please have a way of configuring this option.

Thanks,
G