hide the auth user checkbox on the user edit screen if the user is in the pre-auth role -- reduces UI confusion.

#765994 by hunmonk: Non-authenticated role is hidden in user profile form even when 'Set password' is unchecked

remove unnecessary db_query -- admins validating a user account shouldn't trigger an account login, either.

by hunmonk: add an 'Override destination paramter' setting, enabled by default. this gives admins the option to allow LT to force it's redirect paths over a passed destination parameter. related to solving #604492

#604508 by hunmonk: 'Use two e-mail fields on registration form' setting breaks OpenID registrations. this fixes the LT-related problem, but the openid registration process itself may still be broken -- see #216101

#232467 by mfer, benroot, hunmonk: OpenID logins broken when 'Allow users to login using their e-mail address' setting is enabled.

#492486 by mikehostetler: Array merge of user_register_submit function squashes pre-defined user_register_submit functions.

#564062 by Matthew Davidson, hunmonk: Admin created accounts should have password length validation.

#513372 by hunmonk: 'Account activated' email not sent if new user manually removed from pre-auth role.

#368699 by hunmonk: re-send validation link always appears if non-authenticated role is set to auth user.

#413916 by hunmonk, rfay: New users deleted inappropriately.  this fixes the no-so-well-implemented auto user deletion feature -- much more stable and less dangerous now.

#291006 by hunmonk: Email validate link landing page inconsistency. see logintoboggan_update_6001 for details on this change.