Bug 210357 Can not get sorting key if xtab has a count aggregation binding[1102]
Description: Can not get sorting key if xtab has a count aggregation binding. The filter got the same issue. Build number: 2.3.0.v20071120-0800 Steps to reproduce: 1, New a Cube 2, New a crosstab using the cube 3, Add a aggregation binding on crosstab and select the function to COUNT, leave the datafield empty 4, after step3, goto sort page and add a sorting Expected result: User can get the sorting keys Actual result: The sorting key list is empty and the filter has the same issue
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/olap/util/OlapExpressionCompiler.java
* @param expr
	 * @param bindings
	 * @return
	 * @throws DataException
	 */
	public static Set getReferencedDimLevel( IBaseExpression expr, List bindings )
			throws DataException
	{
		return getReferencedDimLevel( expr, bindings, false );
	}
	/**
	 * Get set of reference DimLevels.
	 * 
	 * @param expr
	 * @param bindings
	 * @param onlyFromDirectReferenceExpr
	 * @return
	 * @throws DataException
	 */
	public static Set getReferencedDimLevel( IBaseExpression expr,
			List bindings, boolean onlyFromDirectReferenceExpr )
			throws DataException
	{
		if ( expr instanceof IScriptExpression )
		{
			return getReferencedDimLevel( ( (IScriptExpression) expr ),
					bindings,
					onlyFromDirectReferenceExpr );
		}
		else if ( expr instanceof IConditionalExpression )