[zen-27] Allow ReCaptchaMailHide to pass
[zen-27] Allow ReCaptchaMailHide to pass

- Fix assertions; expected email hash will vary based on key
- Exception class should not extend Zend_Exception or
  Zend_Service_Exception

weierophinney/ZendService_ReCaptcha,Lansoweb/ZendService_ReCaptcha,akrabat/ZendService_ReCaptcha,srggroup/ZendService_ReCaptcha