Using NS_ENUM for better Swift support
Using NS_ENUM for better Swift support

E-B-Smith/protobuf-objc,E-B-Smith/protobuf-objc,alexeyxo/protobuf-objc,alexeyxo/protobuf-objc,E-B-Smith/protobuf-objc,alexeyxo/protobuf-objc,alexeyxo/protobuf-objc,E-B-Smith/protobuf-objc