[supporter and other payement plugins] Tax & geo management

hi there !

Finished my 2nd network, added supporter, and then.... big problem !!!!

The Tax management, which does not apply in case of international payment !

But this is not "optionized" in the supporter settings !!! And this is a problem since I will have international payments (hope so !) and problem with tax management !

well, to be added with currency management looool :wink: