title: Can't get the original_application_version from the App Store Receipt in iOS 7
body: <p>I'm trying to implement a seamless transition from paid to freemium model for my current customers, but having problems getting the original_application_version from the receipt.</p>
  
  <p>My app is iOS 7 only and, as you may know, Apple introduced the Unified Receipt in iOS 7, which, as stated, should contain information about the original purchase made by user. So my idea was the following:
  1. Decode the receipt.
  2. Check if the original purchase was made before this new freemium version.
  3. If yes - unlock all IAPs.</p>
  
  <p>As stated in the docs the receipt should have this "Original Application Version" field ("The version of the app that was originally purchased."). It's also said that "In the sandbox environment, the value of this field is always “1.0”." But for some reason this is not the case for me.</p>
  
  <p>So, my question is: did someone had any luck getting this value?</p>
  
  <p>I tried to use DHAppleReceiptParser (<a href="https://github.com/DarkHorseComics/DHAppleReceiptParser">https://github.com/DarkHorseComics/DHAppleReceiptParser</a>) and RMStore (<a href="https://github.com/robotmedia/RMStore">https://github.com/robotmedia/RMStore</a>) to parse the receipt, both are giving me empty value for this field. I'm also looking for this value in ASN.1 Field Type 19, maybe there is another field I can use for my purpose?</p>