prd3-sanity1

Hello UBL TC,

I've just uploaded a preliminary (and incomplete) sanity check of
PRD3 to:

   http://ibiblio.org/bosak/ubl/prd3-sanity1.zip

Missing from this build:

 - ASN.1 (expected from Paul Thorpe)

 - Corrected CreditNote sample instance (expected from Peter
   Borresen)

As yet untested (will do later today):

 - Validation under Linux

Editorial:

 - Still need to update dates and package refs (will do later
   today)

Jon