8.21.0

* Feature: Support for the following new recurring transactions:
CreatePlan, UpdatePlan
* Feature: Support for the following new gift card transactions:
Activate, Deactivate, Load, Unload, Balance Inquiry
* Feature: Gift card responses are now returned as part of
authorzationResponse, authReversalResponse, captureResponse,
forceCapture, captureGivenAuthResponse, saleResponse, creditResponse
* Feature: fraudResult is now returned as part of captureResponse,
forceCaptureResponse, captureGivenAuthResponse, creditResponse