* Add methods to finish transactions
* Add a method to get the product descriptions from the App Store
* Improve the documentation of a transaction structure
* Add a tutorial for In App Purchase
* Fix typo in In-App Purchase tutorial
* Fix style of In-App Purchase files
* Fix In-App-Purchase product structure conversion in amr64
* Fix code style in In-App Purchase tutorial documentation
* Fix typos in In-App Purchase documentation
* Fix typo in In-App Purchase spec
* Slight style fixes
