move contribution and delegator methods to application_controller

these methods are used on all controllers :)
move these filter to application controller
move IPN to a notifications_controller
fix spec
change ajax request type

change ajax request type when user has selected a saved credit card
credit_card_base controller

create a controller to handle with default methods to made a
credit_card transaction
credit card controller to handle with credit card transactions
create subscription controller to handle with subscription payments
remove credit_card and subscriptions from pagarme_controller
move slip payment to slip controller
pagarme controller only handle with review
fix typo error