Change singleSignOn to procesSignOn

SSO was originally used for a SSO plugin. The backend has since been
refactored to support other authentication backends.

include/class.auth.php

@@ -132,8 +132,7 @@ abstract class AuthenticationBackend {
         Signal::send('auth.login.failed', null, $info);
     }
 
-    function singleSignOn(&$errors) {
-        global $ost;
+    function processSignOn(&$errors) {
 
         foreach (static::allRegistered() as $bk) {
             // All backends are queried here, even if they don't support

scp/login.php

@@ -37,7 +37,7 @@ if($_POST) {
 }
 // Consider single sign-on authentication backends
 else if (!$thisstaff || !($thisstaff->getId() || $thisstaff->isValid())) {
-    if (($user = StaffAuthenticationBackend::singleSignOn($errors))
+    if (($user = StaffAuthenticationBackend::processSignOn($errors))
             && ($user instanceof StaffSession))
        @header("Location: $dest");
 }

view.php

@@ -22,7 +22,7 @@ if (!$thisclient || !$thisclient->isValid()) {
     // Try autologin the user
     // Authenticated user can be of type ticket owner or collaborator
     $errors = array();
-    $user =  UserAuthenticationBackend::singleSignOn($errors);
+    $user =  UserAuthenticationBackend::processSignOn($errors);
     if ($user && $user->getTicketId())
         @header('Location: tickets.php?id='.$user->getTicketId());
 }