[#4622] - Data source types are not automatically available for query input controls

Custom data sources add query languages that JasperServer can use with reports. They do not automatically appear in the list of query languages available when defining query input controls, as the list is hard coded into the screen definition and has to be changed manually - see WEB-INF/flows/queryBeans.xml.

The enhancement is to make all data source types automatically available to query input controls, including custom data sources.

There are issues with this general need: see enhancement http://jasperforge.org/projects/jasperserver/tracker/view.php?id=4621