Bug 139346 Using isTopN in table inside list group header doesn't work.
Description: Using isTopN in table inside list group header doesn't work. Steps to reproduce: 1.Insert a list with a group 2.Insert a table to list group header 3.Using Total.isTopN(row[],2,null,0) as filter expression in table item. 4.Preview Result: Only the first group displayed top 2 records, other groups kept display all records.
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/impl/QueryExecutor.java
List computedColumns = null;
		    
			computedColumns = this.dataSet.getComputedColumns( );
			if ( computedColumns == null )
				computedColumns = new ArrayList();
			if ( computedColumns.size() > 0 || temporaryComputedColumns.size( ) > 0 )
			{
				IResultObjectEvent objectEvent = new ComputedColumnHelper( this.dataSet, computedColumns, temporaryComputedColumns);
				odiQuery.addOnFetchEvent( objectEvent );
				this.dataSet.getComputedColumns().addAll(temporaryComputedColumns);
			}
	    	if ( dataSet.getEventHandler() != null )
	    	{
	    		OnFetchScriptHelper event = new OnFetchScriptHelper( dataSet ); 
	    		odiQuery.addOnFetchEvent( event );
		    }
	    	
		    if ( dataSetFilters.size( ) + queryFilters.size( ) + multipassFilters.size() > 0 )
		    {
		    	IResultObjectEvent objectEvent = new FilterByRow( dataSetFilters, queryFilters, multipassFilters,
		    			dataSet );
		    	odiQuery.addOnFetchEvent( objectEvent );
		    }
		    
			
		    odiQuery.setMaxRows( this.baseQueryDefn.getMaxRows() );
		}
		finally
		{