Common Base Type

Hi Dan,

We're doing a lot of work around CreditNotes and Invoices and this change would reduce the amount of duplicate code we end up dealing with.

I had to make a change to the code that identifies the type so it checks the inheritance tree rather than just using the string name of the Type.

If you can think of a better name for this new type then let me know. TradingTransaction was the best I could come up with!

Regards,
Matthew