Revise "Photo - Amazon" Extractor #130 #132

* Add support for new product page and some product photos #132
* Remove overwriting ctx.target #130
* Remove old XPath expressions
* Use document.createElement('img') instead of MochiKit's IMG()
* Add getImageURL(), getTargetURL(), getMainImageThumbnail(), getImageID(), getLargeImageURL()

Close #130, Close #132