CSVI virtuemart google base export Tax's changes

Google base import has changed their tax format for product import, to implement these changes in Virtuemart CSVI export you need to make some code changes.

1. Change the Default fields in the google base export
   
   1. Change the custom field g:tax_region to g:tax and give it your required values semi-colon separated in the format of (Country:Region:Rate) i.e. "US:Colorado:5.00"
      
2. Remove the custom field g:tax_percent

around line 113 in csvi_class_xml_froogle.php in the file
administrator/com_csviimproved/helpers/xml
add the following case to the function ContentText

case 'g:tax':
                        list($country, $service, $rate) = split(":", $content);
                        $this->contents = '
                        <g:country>'.$country.'</g:country>
                        <g:region>'.$service.'</g:region>
                        <g:rate>'.$rate.'</g:rate>
                        <g:tax_ship>n</g:tax_ship>
                        ';
                    break;