Provide better information on invalid activation url. Make activation and password reset templates look the same.

Set a temp password on user activation so users who skip setting one can use the password reset function.

Address field no longer requeried so remove fake address. Remove non existing groups-role from mapping in user migration.

Add next query to social login link so next redirect is done when needed. Set SOCIAL_AUTH_GOOGLE_OAUTH2_WHITELISTED_DOMAINS to STAFF_EMAIL_DOMAINS if not set.

Issue: #170 Minor fixes to e-mail templates. Comma efter Dear name, Space after signature divider. Line break fixes.