API updates
Merge branch '8.x-1.x' into personalization
Rename dependencies
Removed simplenews_permission()
Added form modes, hiding email from account form
Remove fieldable flag, use ::neutral() instead of ::create().
Replaced url()/l()/Url::generateFromUrl() calls

Also tiny SubscribeTest corrections.
Merge branch '8.x-1.x' into personalization

Conflicts:
	src/Form/SubscriptionsPageForm.php
Moved up getOnlyNewsletter() to SubscriberFormBase, fixed actions #access