String "Close window" denies translation

The string "Close window" in smileys.js is hardcoded, so it may not be localized. In general, JS strings should be wrapped as Drupal.t('string') - but in this instance it seems to break the script (on my install with FF at least), so someone with more JS skills is needed to fix this properly.

As a temporary hack for my site, I went with the localized string hardcoded instead, but that's no solution, really. We need to fix this.