WP Global Screen Options <= 0.2 - Cross-Site Request Forgery to Screen Options Update

The WP Global Screen Options plugin for WordPress is vulnerable to Cross-Site Request Forgery in all versions up to, and including, 0.2. This is due to missing nonce validation on the `updatewpglobalscreenoptions` action handler. This makes it possible for unauthenticated attackers to modify global screen options for all users via a forged request granted they can trick an administrator into performing an action such as clicking on a link.