Disable ALL cookie warnings and hints

2018 - update: As stated by @ElegyD in the comments:

Prebake hans't been updated in 2 years. uBlock Origin now uses Fanboy's Cookiemonster List instead, you can enable it in the Annoyances category.

Late 2015 update. The way to go nowadays appears to be with uBlock Origin, outperforming AdBlock and its variants.

It has an option to enable:

• EU: Prebake - Filter Obtrusive Cookie Notices‎

There is a Firefox/Chrome add-on called I don't care about cookies that will help you to remove these warnings from many thousands of, as it says, "infected" websites :)

If you use AdBlock or AdBlock Plus extension for Chrome, Firefox, etc. you can add a custom list filter to it that will block these pop-ups. Some ad blockers have built-ins list filters that block this and others annoyances.

I personally use Prebake. To use it just make sure you have one of the supported adblockers, access the site and click in the "Subscribe to the Prebake list filter".

CookiesOK is able to detect and handle several often used scripts such as CookieCuttr and CookieGuard. Developer can also make their script compatible with the extension.

There are extensions available for Chrome, Firefox and Opera.