* Primary email should be activated together with user account when
'RegisterEmailConfirm' is enabled.

* To fix the existing error state. When 'RegisterEmailConfirm' is enabled, the
admin should have permission to modify the activations status of user email.
And the user should be allowed to send activation to primary email.

* Only judge whether email is primary from email_address table.

Signed-off-by: Meano <meanocat@gmail.com>

Signed-off-by: Andrew Thornton <art27@cantab.net>