ios/macos签名证书类型

Reference

1. https://developer.apple.com/library/mac/documentation/IDEs/Conceptual/AppDistributionGuide/MaintainingCertificates/MaintainingCertificates.html#//apple_ref/doc/uid/TP40012582-CH31-SW41
2. http://stackoverflow.com/questions/13196291/difference-between-mac-developer-and-3rd-party-mac-developer-application