This adds the ability for non-registered users to disallow updating profile pictures by content editors (aka picture opt-out).
Together with [https://yellowgrass.org/issue/conf.researchr.org/803](Add easy management of profile pictures), it allows them to delete profile pictures not uploaded by them.

This page is linked from emails with notifications, but should also be linked from a new notification email sent when a profile picture is not uploaded by the data subject itself.

Submitted by Elmer van Chastelet on 26 April 2018 at 09:43