cleans up payment for issue #291

cleans up payment for issue #291
cleans up paypal_payment for issues #183 & #291

cleans up paypal_payment for issues #183 & #291
cleans up amazon_payment for issues #183 & #291

cleans up amazon_payment for issues #183 & #291
cleans up billing for issues #183 & #291

cleans up billing for issues #183 & #291