Remove min iOS deployment target
Use unsafe_unretained instead of weak for iOS earlier than 5.0
Use weak if it is available
Adding root-level workspace
Adding CargoBay files as independent group in workspace
Merge pull request #6 from l4u/version

Compatibility with iOS 4.3
Merge branch 'master' of https://github.com/mattt/CargoBay
[Issue #5] Initial implementation of improved receipt verification
Making Security framework optional
Treating status 21006 as success

Removing CargoBay error domain
The request should be a POST to iTunes verifyReceipt API end point instead of a GET.
Expands verify transaction interface to support password, needed for verifying auto-renewable subscription receipt.
Parameter encoding should be set to JSON for receipt verification client.
Handles exception message in receipt verification failure optionally to prevent crash when a failure does not give exception message. (e.g. 21007)
extendedValidation might be false and error will not be set. Follow more closely to to `ValidationController` in this aspect.
Adds receipt validation.
Implements `doTransactionDetailsMatchPurchaseInfo:withPurchaseInfo:`.

This version differs from Apple's implementation in that it checks for all optional cases except `requestData`.
The reason `requestData` is avoided is because this is a field Apple reserve for future uses and thus its behaviour is subject to change. Guarding against it will make the code less future proof.
A detail explanation is available as inline comments.
Adding note about mission-critical sister projects
Specify code sections.
Differentiates between production and sandbox receipt verification base URL string.

Mark sandbox receipt verification base URL string as unused for now.