title: Is there an API to cancel an auto-renewable subscription?
body: <p>I don't currently use any apps that have an in app subscription, so I am not sure what the UI looks like in iTunes when do an <a href="http://developer.apple.com/library/ios/#documentation/NetworkingInternet/Conceptual/StoreKitGuide/RenewableSubscriptions/RenewableSubscriptions.html#//apple_ref/doc/uid/TP40008267-CH4-SW2" rel="noreferrer">in app renewable subscription</a>. </p>
  
  <p>I assumed there was an api, given a receipt id or original transaction id, to cancel the auto-renewable subscription from within the application. It doesn't look like this exists. </p>
  
  <p>Am I missing something or do users cancel auto-renewable subscription through their iTunes account settings? This just isn't the developer's responsibility?</p>