Updated Core Components Parameters Schema

Please find attached an update to the (draft) 2.0 
Core Components Parameters Schema, as for my
action item at the last Pacific TC call.

I just changed a few things in Gefeg's (David's) 
schemas generated on Mar 29th, these were:

1. changed namespace versions to '2.0'
2. deleted date generated (for later inclusion)
3. The main change, minOccurs for 'Definition': 
     from
<xsd:element ref="Definition" minOccurs="1" maxOccurs="1"/>
     to
<xsd:element ref="Definition" minOccurs="0" maxOccurs="1"/>
This is needed since Definition may be not included in codelist schemas
(hence validation errors when validating within documentation in 
UBL 1.0 xsd, rather than xsdrt, schemas).

I believe we have resolved to import this schema (or a tool-generated one
like it) into BIE schemas but not into the DT schemas.

All the best

Steve