[kronolith] make guests see all available calendars

[Jason Rust]

Actually, I think you can do this sort of thing from directly from the
prefs.php file with something like this:
// store the calendars to diplay by default
$_prefs['display_cals'] = array(
    'value' => 'a:2:{i:0;s:32:"398299d9112356b4be4cce06ec449bdf";i:1;s:32:"598299d9112356b4be4cce06ec449bdf";}',
    'locked' => false,
    'shared' => false,
    'type' => 'implicit');

// if it's a guest user then they can only view the public calendars
if (!Auth::isAuthenticated()) {
    $_prefs['display_cals']['value'] = 'a:1:{i:0;s:32:"598299d9112356b4be4cce06ec449bdf";}';
    $_prefs['display_cals']['locked'] = true; 
}

-Jason