Ad Highlighter for AutoFR

Ad Highlighter has been modified to work with AutoFR, using its perceptual-adblocker only.

We add/modified the following:

• Event listeners to get the total ads detected and information like the src url of the iframes. See content.js.
• More AdChoice hashes. See adchoices_hashes.js.
• Improved method of getting background image position and sizes. See getBackgroundImagePos() from image_search.js.

For information about how it works, see Perceptual-Adblocker's README.