Allow for both VAT to show in webshop

It would be nice to have the ability to show both VAT. Inclusive and Exclusive along with the VAT percentage.

for example:
- 100 euro excl. 21% VAT - 121 euro incl. 21% VAT

it's not easy possible now. and when looking at the code it's a lot fiddling around because now most of the code is an if else statement from a CLASS constant. So implementing the feature above is better because when i update your package my changes are gone.