PO backorder suffix element added to ReceiveDelivery BOD

The element, BackorderSuf, is added to the User Area section of the inbound ReceiveDelivery BOD.

An example of the new User Area element populated within the BOD:

<LineNumber>3</LineNumber>
<UserArea>
     <Property>
        <NameValue name="BackorderSuf" type="SX">1</NameValue>
     </Property>
</UserArea>

This new element is intended for use by a future enhancement to the integration to Service Management.