Issue #1630822 by mrkrettan: Fixed checking for the Klarna API file.
Issue #1679136 by ojohansson: Fixed not loading the Klarna invoice terms.
by ojohansson: Hide the invoice terms link until the terms has been properly initiated.
by ojohansson: Added a setting for the invoice fee amount.
Changed the settings implementation.
Only add the shipping address if Commerce Shipping is enabled.
Decode messages from Klarna to UTF-8.
Altered the response handling from addTransaction.
Update the $charge array just before we initiate the transaction.
Send the Commerce Order ID to Klarna.
Normalize the settings when initiating Klarna.
Get the billing and shipping address directly from the Commerce Order object, rather than wrapping them once again.
