Add emails to default users to prevent fatals on 'unblockage'

Problem/Motivation

When a user is unblocked via the UI (or probably Drush too) the site fatals because it's expecting to be able to process an email, of which none exists.

Steps to reproduce

Edit an existing user, make the account active and save.

Proposed resolution

Rather than using a patch to check the presence of an email address we're favouring just providing default 'faux' emails against each user. Removes the need to monitor the patch / core status and remove in later releases.