Adding InvariantCulture for some <decimal?>
Adding InvariantCulture for some <decimal?>

In the back office some product features were viewed as 0 if product is retrieved from MerchelloProductIndexes
rasmusjp/Merchello,ProNotion/Merchello,Merchello/Merchello.Bazaar,ProNotion/Merchello,ProNotion/Merchello,Merchello/Merchello,rasmusjp/Merchello,Merchello/Merchello,Merchello/Merchello.Bazaar,clausjensen/Merchello,rasmusjp/Merchello,Merchello/Merchello,clausjensen/Merchello,Merchello/Merchello.Bazaar,clausjensen/Merchello