Adds public setters to invoice and order numbers
Added SalesPreparation "Finalizing" event.
Added event handler to record taxation record with AvaTax after a successful sale.  Build scripts.
Merge pull request #791 from rustyswayne/1.4.0

Added event handler to record taxation record with AvaTax after a successful sale.
Merge remote-tracking branch 'merchello/1.4.0' into 1.4.0
Completed initial version of AvaTax provider.  Still to do is the cancel request.
Merge pull request #792 from rustyswayne/1.4.0

Completed initial version of AvaTax provider.
Merge remote-tracking branch 'merchello/1.4.0' into 1.4.0
Sale view adjustments.