hides options if not enabled
turn the urls for HOP into options
adds a return url
adds a Post Back Url option setting
adds a cancel url
sets an option to use a cancel url
set up an option to clear the cart on cancel or not
make it an option to use the return url
remove the option to set a custom postback url.. not needed
set the proper sorting numbers
taking a stab at repopulating on a failed transaction
clear_cart_oncancel doesn't need to be depended
implements the option to clear the cart
Merge pull request #2 from jeremyBass/master

sets up new options that will alow for matching of proxed cybersource gateways