[FIX] Update Polish VAT rates

            
Since 2011 there are new VAT tax rates 
see current rates here:
http://europa.eu/youreurope/business/managing-business/paying-taxes/poland/

lp bug: https://launchpad.net/bugs/1191742 fixed

bzr revid: t.motylewski@macopedia.pl-20130704172605-naivnilf60t17bnn