Developers: Microsoft Dynamics GP 2013 Service Pack 2 moves the Vendor and Customer Combiner & Modifier into core code

This is a reposting of an article I originally wrote on my Developing for Dynamics GP blog.
I had a case today where a developer was having issues when using the Customer Combiner. This functionality was part of PSTL (Professional Services Tools Library) and as of Microsoft Dynamics GP 2013 Service Pack 2 is now part of core code.
