Add user.created and user.last_login to User details and list in the admin interface

part 1 of #1889 (closed)

changed milestone to %Arkindex 1.7.2

requested review from @erouchet

assigned to @mlbonhomme

changed title from Add user.created and user.last_login to User and Group admins to Add user.created and user.last_login to User details and list in the admin interface

changed the description

merged