XNAT-4249: '...timed out...' message won't display on login page unless user's...

XNAT-4249: '...timed out...' message won't display on login page unless user's last session was terminated due to inactivity. Spawner changes: for 'href', 'src', and 'action' properties, values starting with */ will ensure the path starts at the site root; also added 'name' attribute to form panels.