* Moved email changing from sp:Preferences to new sp:ChangeEmail, which requires...

* Moved email changing from sp:Preferences to new sp:ChangeEmail, which requires confirming the user password. This reduces the impact of session hijacking, which was increased slightly with r86482. Changing a password already required confirming the old one. This change closes the loophole of changing the email address and then doing a reset.
* Parse 'mailerror' message correctly