Causes a tiny DOS attack on my development environment.

The script checks very aggressively for changed files, and it causes my HTTPD process to spike to 30-40% CPU usage every few seconds. It also strains the browser. I suggest three changes:

1. Increase the timeout to be 5-10 seconds.
2. Make the timeout configureable
3. Allow "0" to be the timeout, and add a floating button to the page that checks and refreshes the CSS when the user clicks that button.