Bug 182680 Use feature of new Aggregation framework of Data Engine.
DataEngine will implement new aggregation framework in 2.2.0RC0. After the implementation is finished Engine should go ahead to use new column bindings in definition of map/highlight.
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/impl/ExprManager.java
{
		bindingExprs = new ArrayList( );
		autoBindingExprMap = new HashMap( );
		entryLevel = OVERALL_GROUP;
		this.baseQueryDefn = baseQueryDefn;
	}
	/**
	 * @param resultsExprMap
	 * @param groupLevel
	 */
	public void addBindingExpr( String groupKey, Map resultsExprMap, int groupLevel )
	{
		if ( resultsExprMap == null )
			return;
		
		Context cx = Context.enter( );
		try
		{
			if ( groupKey != null )
			{
				CompiledExpression ce = ExpressionCompilerUtil.compile( groupKey,
						cx );
				if ( ce instanceof ColumnReferenceExpression )
				{
					ColumnReferenceExpression cre = ( (ColumnReferenceExpression) ce );
					groupKey = cre.getColumnName( );
				}
			}
			
			bindingExprs.add( new GroupBindingColumn( groupKey,