workflow registration

Replace access denied on user/register for logged-in users with a redirect

Best resource on this that I've found:

logged-in user + /user/register -> access denied
http://drupal.org/node/118498

There's no reason for this-- even user #1 gets access denied here, and users who could go to admin/user/user/create -- access denied might be technically correct, you can't re-register, but it's nonsensical and annoying.