Machine auth without creating a machine user

[E-ThanG]

Is your feature request related to a problem? Please describe.
It'd be nice if the Admin UI Users tab only contained people, not machines/computer accounts. Also, machines don't have an email address, so the User form is never happy about machines being there.

Describe the solution you'd like
Add a configuration option in the connection profile that disables the do_person_create function call for machine authentication.