On com_sales, made the following changes:
-changed position of rendered receiptactions module from 'right' to 'content'.
-changed css of receiptactions view to have buttons on the same line.
-added a config option to email customers a copy of void or return receipts automatically.
-added the email_receipt() function to the return class.
-added functionality to automatically email email a receipt to the customer when a sale is tendered, voided, or returned.
-added receipt action buttons to the return receipt view.