Proposal: Enhance database fields

Hi all,

attached is a proposal to change database fields. Currently, database 
fields have a database-name attribute to identify the database. 
Additionally, we want to allow
1) an XLink to an actual database file, or
2) a connection resource (e.g. a JDBC pseudo-URL)
Because of the XLink, the new attributes are in a child element, instead 
of  the actual field element themselves.

Sincerely,
Daniel