Updated to use PHG affiliate links, as TradeDoubler is no longer used by iTunes

See http://www.apple.com/itunes/affiliates/resources/phg-transition.html for more info.

* Replaced partnerId and tradeDoublerId properties with a single affiliateToken property.
* Added explicit CC_LONG cast to suppress warning when compiling for 64-bit.
* Added to contributor list, and updated README to reflect changes to affiliate token properties.