Added comment that methods for NSURLSession swizzling are private/internal
Added comment that methods for NSURLSession swizzling are private/internal

apigee/apigee-ios-sdk,RobertWalsh/apigee-ios-sdk,RobertWalsh/apigee-ios-sdk,RobertWalsh/apigee-ios-sdk,developerdave/apigee-ios-sdk,developerdave/apigee-ios-sdk,apigee/apigee-ios-sdk,apigee/apigee-ios-sdk,pauldardeau/apigee-ios-sdk,pauldardeau/apigee-ios-sdk,RobertWalsh/apigee-ios-sdk,RobertWalsh/apigee-ios-sdk,apigee/apigee-ios-sdk,apigee/apigee-ios-sdk,apigee/apigee-ios-sdk,pauldardeau/apigee-ios-sdk,developerdave/apigee-ios-sdk,developerdave/apigee-ios-sdk,developerdave/apigee-ios-sdk,developerdave/apigee-ios-sdk,RobertWalsh/apigee-ios-sdk,pauldardeau/apigee-ios-sdk