Refactored and fixes issue with cart messaging

@tsanko made some refactoring changes and also fixed the issue with success message not shown. Please take a look and pull in.
Hmmmm .... while debugging I inspected "translateFilter('message.CART_TSANKO')" and the result was 'message.CART_TSANKO' ... it's not translating even if I request correct key w/ some value (this used to work as before I was displaying values from lang file)