Admin users can delete other admin users

Hi,

This is both a bug and a new feature request.  Currently, if I am the main admin of the system, and I create new admins, they can delete me, as well as other admins (didn't try to delete the last admin, can't think of why not to).

My point:
1. Make that the original Admin can not be deleted by others
2. Make a "Co Admin" type. These have the same Admin rights, but can not delete Admins.

Saar