Added support for the Magento API "multiCall" call
small bug with checking the return codes of multicalls. Check for Hashes first.
rescue RuntimeError for HTTP requests and retry a few times
Added parent_id to Category.create()

Category create now takes a parent_id and attributes for create
Adding Giftcard Account class.

Initial addition of Giftcard Account class with list and create methods.
Adding list_of_additional_attributes method to Product class.
Adding info, update, and update_attributes (multiple attributes) methods to Product Attribute class.
Adding MaskCcNumber API method.
Adding api_path method for Invoice to set the correct api path for Magento.
Merge gbillingsley/magentor.

* gbillingsley:
  Adding MaskCcNumber API method.
  Adding info, update, and update_attributes (multiple attributes) methods to Product Attribute class.
  Adding list_of_additional_attributes method to Product class.
  Adding Giftcard Account class.
Merge branch fw42/magentor.

* fw42/magentor:
  rescue RuntimeError for HTTP requests and retry a few times
  small bug with checking the return codes of multicalls. Check for Hashes first.
  Added support for the Magento API "multiCall" call