Prevent the CAS module from regenerating the session id on each request.

git-svn-id: file:///tmp/wdn_thm_drupal/branches/drupal-7.x@68 20a16fea-79d4-4915-8869-1ea9d5ebf173

sites/all/modules/unl/unl_cas.module

@@ -18,8 +18,10 @@ function unl_cas_init()
             if (!$user) {
                 $user = unl_cas_import_user($username);
             }
-            $GLOBALS['user'] = $user;
-            user_login_finalize();
+            if ($GLOBALS['user']->uid != $user->uid) {
+                $GLOBALS['user'] = $user;
+                user_login_finalize();
+            }
         }
     }
 }