3493 Can't change username capitalization in Firefox if login info saved

http://code.google.com/p/otwarchive/issues/detail?id=3493

This is the stupidest fucking thing I have ever heard, to borrow from a TDS or TCR segment: Firefox's password manager ignores `autocomplete="off"` when a user name field and a password field appear in that order and instead happily fills in the saved information. So I moved the password field to the top of the form (which is where it is on the Change Email form). I also stuck an `autocomplete="off"` on the New User Name field so it doesn't even suggest anything but the Password field will still be automatically completed.