[dnc-wb] recursively replace all ArchetypeExpression with
QueryExpression in query requests.  

[sql-semantic-mediator-xml] add LTRIM/RTRIM to the sql generation for
lab tests.

[sql-semantic-mediator-lexevs] refactor SQLSemanticMediator to use
LexEVS models. Move mediator.properties from classpath to the working
directory, so it can be edited directly on the source site. 

Updated some unit tests.