Fix hardcoded path
No need to depend on RMStore.h just for receiptURL
Mark RMAppReceipt availability
Merge pull request #20 from xgil78/master

Added isAutoRenewableSubscriptionValid:forDate: to RMAppReceipt.
Style changes and only check cancellationDate of the last transaction
Expand documentation
valid > active (per Apple's documentation)
RMAppReceiptIAP  isActiveAutoRenewableSubscriptionForDate:
Rename to containsActiveAutoRenewableSubscriptionOfProductIdentifier
Link to issues
Retry if verification fails