Allow to renounce inputs resulting from expressions in the ExpressionParser
requested to merge goetz/athena:ExpressionParser_master_renounce_support_for_expression_parser into master
The renounceInput of the IDataHandleHolder is overloaded in the ExpressionParserUser template to propagate the inputs which are to be renounced to the proxy loader. These inputs are memorised, and taken into consideration at the time the proxy loader is declaring the data needed for its expressions.