major step forward for 1.4

[Chris Travers <..hidden..>]

Hi all;

I have just committed unit tests on the new COGS stored procedures.
There are 93 tests, covering 16 invoices, with 4 overall test runs.
These test AR before AP, AP before AR, mixed workloads and reversals.

I think this is a major step forward in moving away from code that's
difficult to test towards code that is robust and testable.

Best Wishes,
Chris Travers