Display VAT on checkout pages

[Raj Saini]

Hi,

I am working a e-commerce application and using new VAT implementation. 
I have a problem showing the VAT adjustment as TAX on cart/checkout 
pages. ShoppingCart#getTotalSalesTax and in turn 
OrderReadHelper#getOrderTaxByTaxAuthGeoAndParty always returns zero as 
it does not consider the OrderAdjusment of VAT_TAX type.

I am working on enhancements and trying to find the best way so that it 
is generic and my work could be contributed back to the community.

My question is should we add other method in ShippingCart and 
OrderReadHelper classes for VAT or enhance the existing methods to 
include the OrderAdjustments of VAT_TAX type.

Thanks,

Raj