Small update

I've updated the filebase here and at mosforge.net. I've fixed an error in the product class (a new product couldn't be assigned to a category). The PayPal button now redirects to PayPal with the order total amount only (without shipping). And last: the email with an Download-ID now contains direct links to the download page with the download ID already filled into the text field. So the user doesn't need to copy and paste....