enable simple registration+solution

Link to "Sign Up" (not "Request Account" as before) if "Anyone" has permission to create Account Request cards.

If "Anyone" has the "create_accounts" permission, then:

1. Sign Up uses AccountRequest+*tform
2. automatically converted to user

otherwise, procedure is the same as before, plus some more configurable notifications (see move most configuration options into cards)

Also, as part of this fix, you now never add a password right when adding an account - just the email.