Fixed registration - make sure that email validation is against all e-mail

addresses, not just primary ones. Make sure that newly registered users
do not clobber existing e-mail addresses.

htdocs/lib/user.php

@@ -169,7 +169,7 @@ function set_profile_field($userid, $field, $value) {
     // specified one
     if ($field == 'email') {
         try {
-            $email = artefact_instance_from_type('email');
+            $email = artefact_instance_from_type('email', $userid);
         }
         catch (ArtefactNotFoundException $e) {
             $email = new ArtefactTypeEmail();

htdocs/register.php

@@ -372,7 +372,7 @@ function register_validate(Pieform $form, $values) {
     // The e-mail address cannot already be in the system
     if (!$form->get_error('email')
         && (record_exists('usr', 'email', $values['email'])
-        || record_exists('usr_registration', 'email', $values['email']))) {
+        || record_exists('artefact_internal_profile_email', 'email', $values['email']))) {
         $form->set_error('email', get_string('emailalreadytaken', 'auth.internal'));
     }
     
@@ -403,6 +403,7 @@ function register_submit(Pieform $form, $values) {
         insert_record('usr_registration', $values);
 
         $user =(object) $values;
+        $user->admin = 0;
         email_user($user, null,
             get_string('registeredemailsubject', 'auth.internal', get_config('sitename')),
             get_string('registeredemailmessagetext', 'auth.internal', $values['firstname'], get_config('sitename'), $values['key'], get_config('sitename')),