Warn users if they use more than 10 levels

The default tagadelic.css supports 10 levels of sizes but on the config page the user can choose any number. We chose 14 and as a result the largest tags got no styling and were the smallest. It would be great to add a description to the level settings field telling people that they will need to add their own css if they go beyond 10 levels, or to do so with a drupal_set_message after the form is submitted.