Adds copyFrom() method to common address item to simplify address handling
Fixes parameter type in method documentation
Returns always a string for the customer ID
Implements saving new delivery addresses as customer delivery address automatically
Improves processing payment service
Activates "en" locale for unit tests to be able to enter new addresses during the checkout process
Merge pull request #244 from nsendetzky/master

Implements saving new delivery addresses entered during the checkout processas customer delivery address automatically