New Feature: E-mail payment notifications

New API feature allows you to receive an e-mail notification whenever you receive a payment. A new optional parameter email has been added to the address creation request, when you can optionally add an email address where a payment notification will be sent to. The payment notification email will contain the amount and TXID of the payment. If you do not set an email address, everything will work just like before, therefore not breaking backwards-compatibility. The documentation page has been updated with the new parameter. We hope you enjoy this new feature!